2. Summary of significant accounting policies

Basis of Consolidation and Presentation

        The accompanying consolidated financial statements include the accounts and operations of the Company. All intercompany accounts and transactions have been eliminated. The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP"). The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements. Actual results could differ from these estimates and assumptions.

        The prior year consolidated balance sheet at December 31, 2008 and consolidated statement of cash flows for the year ended December 31, 2008 have been adjusted to correct immaterial errors related to the elimination of intercompany receivables and payables. The corrections reduced the accounts receivable and accounts payable line items in the December 31, 2008 consolidated balance sheet by $236 million, which correspondingly impacted the change in accounts receivable and accounts payable in the consolidated statement of cash flows for the year ended December 31, 2008 by $236 million. These corrections had no impact on net income, earnings (loss) per share, working capital or net cash provided by operating, investing and financing activities.

        Certain reclassifications have been made to prior year amounts to conform to the current period presentation.

        The Company considers events or transactions that occur after the balance sheet date, but before the financial statements are issued to provide additional evidence relative to certain estimates or to identify matters that require additional disclosures.

Cash, Cash Equivalents and Investment Securities

        We consider all money market funds and highly liquid investments with maturities of three months or less when purchased to be cash equivalents.

        Investments designated as available-for-sale securities are carried at fair value based on quoted market prices or estimated based on quoted market prices of financial instruments with similar characteristics. Unrealized gains and losses of the Company's available-for-sale securities are excluded from earnings and reported as a component of other comprehensive income (loss), when credit losses are not expected and the Company does not intend, or it is more likely than not that the Company will not be required, to sell the security prior to recovery of the security's amortized cost basis.

        In general, investments with original maturities greater than 90 days and remaining maturities of less than one year are classified as short-term investments. In addition, investments with maturities beyond one year may be classified as short-term based on their highly liquid nature and because such investments represent the investment of cash that is available for current operations.

        The specific identification method is used to determine the cost of securities disposed with realized gains and losses reflected in investment and other income (loss), net in the consolidated statements of operations.

        The Company's investments include auction rate securities ("ARS"). These ARS are variable rate bonds tied to short-term interest rates with long-term maturities. ARS have interest rates which reset through a modified Dutch auction at predetermined short-term intervals, typically every 7, 28, or 35 days. Interest on ARS is generally paid at the end of each auction process and is based upon the interest rate determined for the prior auction. The majority of our ARS are AAA/Aaa rated, and are typically collateralized by student loans guaranteed by the U.S. government under the Federal Family Education Loan Program or backed by monoline bond insurance companies.

        Our ARS held through UBS AG ("UBS") are classified as trading securities. Investments designated as trading securities are reported at fair value, with unrealized gains and losses recognized in earnings.

        On November 14, 2008, we accepted an offer from UBS, providing us with rights related to our ARS held through UBS (the "Rights"). The Rights permit us to require UBS to purchase our ARS held through UBS at par value, which is defined as the price equal to the liquidation preference of the ARS plus accrued but unpaid dividends or interest, at any time during the period between June 30, 2010 and July 2, 2012. Conversely, UBS has the right, in its discretion, to purchase or sell our ARS at any time until July 2, 2012, so long as we receive payment at par value upon any sale or disposition. If auctions continue to fail, we expect to sell our ARS under the Rights. However, if the Rights are not exercised before July 2, 2012 they will expire and UBS will have no further rights or obligation to buy our ARS. So long as we hold our ARS, t hey will continue to accrue interest as determined by the auction process or by the terms of the Rights if the auction process continues to fail.

        UBS's obligations under the Rights are not secured by its assets and do not require UBS to obtain any financing to support its performance obligations under the Rights. UBS has disclaimed any assurance that it will have sufficient financial resources to satisfy its obligations under the Rights.

        The Rights represent a firm agreement in accordance with the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 815, regarding derivatives and hedging ("ASC Topic 815"), which defines a firm agreement as an agreement binding on both parties and usually legally enforceable, with the following characteristics: (a) the agreement specifies all significant terms, including the quantity to be exchanged, the fixed price, and the timing of the transaction, and (b) the agreement includes a disincentive for nonperformance that is sufficiently large to make performance probable. The enforceability of the Rights should be recognized as a free standing asset separate from the ARS. The Rights do not meet the definition of a derivative instrument under ASC Topic 815, because the underlying securities are not readily convertible to cash. Therefore, we have elected to measure the Rights at fair value under ASC Subtopic 825-10 regarding the fair value option for financial assets and financial liabilities, which permits an entity to measure certain items at fair value, to mitigate volatility in reported earnings from the changes in the fair value of the ARS. As a result, unrealized gains and losses will be included in earnings in future periods. We expect that future changes in the fair value of the Rights will largely mitigate fair value movements in the related ARS. At December 31, 2009, we have classified our investment in ARS held through UBS as a current asset as the expected settlement is June 30, 2010.

• Restricted Cash—Compensating Balances

        Most of our restricted cash relates to a standby letter of credit required by one of our inventory manufacturers to qualify for payment terms on our inventory purchases. Under the terms of this arrangement, we are required to maintain with the issuing bank a compensating balance, restricted as to use, of not less than the sum of the available amount of the letter of credit plus the aggregate amount of any drawings under the letter of credit that have been honored thereunder, but not reimbursed. Restricted cash is included in short-term investments.

• Financial Instruments

        The carrying amount of cash and cash equivalents, accounts receivable, accounts payable, and accrued expenses is reasonable approximation of fair value due to their short-term nature. Our U.S. government agency securities and mortgage-backed securities are carried at fair value with fair values estimated based on quoted market prices or estimated based on quoted market prices of financial instruments with similar characteristics. Both short-term and long-term ARS are carried at fair value with fair values estimated using an income-approach model (specifically, a discounted cash-flow analysis). We carry derivative instruments, including foreign exchange contracts, in the balance sheet as other assets or liabilities at their fair value. The fair value of foreign currency contracts is estimated based on the prevailing exchange rates of the various hedged currencies as of the e nd of the period.

        Activision Blizzard transacts business in various foreign currencies and has significant international sales and expenses denominated in foreign currencies, subjecting Activision Blizzard to foreign currency risk. Activision Blizzard utilizes foreign exchange forward contracts and swaps to mitigate foreign currency exchange rate risk associated with foreign currency denominated assets and liabilities. The foreign exchange forward contracts generally have contractual terms of less than a year. Activision Blizzard does not use foreign exchange forward contracts for speculative or trading purposes. None of Activision Blizzard's foreign exchange forward contracts were designated as hedging instruments under ASC Topic 815. Accordingly, gains or losses resulting from changes in the fair values of the foreign exchange forward contracts are reported as investment and other income ( loss), net in the consolidated statements of operations.

Other-Than-Temporary Impairments

        On April 1, 2009, we adopted prospectively a new accounting standard addressing the evaluation of fixed maturity securities for other-than-temporary impairments. These requirements have altered our policies and procedures for determining impairment charges recognized through earnings. The new standard requires a company to recognize a credit component (a credit impairment) of an other-than-temporary impairment of a fixed maturity security in earnings and the non-credit component in accumulated other comprehensive income (loss) if the company does not intend, or it is more likely than not that the company will not be required, to sell the security prior to recovery of the security's amortized cost basis. The new standard also changes the threshold for determining when an other-than-temporary impairment has occurred on a fixed maturity security with respect to intent and ability to hold the security until recovery and requires additional disclosures. A credit impairment, which is recognized in earnings when it occurs, is the difference between the amortized cost of the fixed maturity security and the estimated present value of cash flows expected to be collected (recovery value), as determined by management. The difference between fair value and amortized cost that is not related to a credit impairment is recognized as a separate component of accumulated other comprehensive income (loss), net of taxes. The adoption of this standard did not have a material impact on our consolidated financial statements.

Concentration of Credit Risk

        Financial instruments which potentially subject us to concentration of credit risk consist principally of cash and cash equivalents and accounts receivable. We place our cash and cash equivalents with financial institutions. At various times, we had deposits in excess of coverage by the Federal Deposit Insurance Corporation ("FDIC"), or the equivalent agencies in overseas jurisdictions, at these financial institutions.

        Our customer base includes retail outlets and distributors, including mass-market retailers, consumer electronics stores, discount warehouses, and game specialty stores in the United States and countries worldwide. We perform ongoing credit evaluations of our customers and maintain allowances for potential credit losses. We generally do not require collateral or other security from our customers. We had two customers, Wal-Mart and GameStop, who each accounted for approximately 10% of the consolidated revenues for the year ended December 31, 2009 and accounted for approximately 18% and 10% of consolidated gross receivables at December 31, 2009, respectively.

        For the year ended December 31, 2008, we had two customers, Wal-Mart and GameStop, who each accounted for approximately 11% of the consolidated net revenues and accounted for approximately 15% and 9% of consolidated gross receivables at December 31, 2008, respectively.

Software Development Costs and Intellectual Property Licenses

        Software development costs include payments made to independent software developers under development agreements, as well as direct costs incurred for internally developed products.

        We account for software development costs in accordance with the FASB guidance for the costs of computer software to be sold, leased, or otherwise marketed ("ASC Subtopic 985-20"). Software development costs are capitalized once the technological feasibility of a product is established and such costs are determined to be recoverable. Technological feasibility of a product encompasses both technical design documentation and game design documentation, or the completed and tested product design and working model. Significant management judgments and estimates are utilized in the assessment of when technological feasibility is established. For products where proven technology exists, this may occur early in the development cycle. Technological feasibility is evaluated on a product-by-product basis. Prior to a product's release, we expense, as part of "cost of sales—sof tware royalties and amortization", capitalized costs when we believe such amounts are not recoverable. Capitalized costs for those products that are cancelled or abandoned are charged to product development expense in the period of cancellation. Amounts related to software development which are not capitalized are charged immediately to product development expense.

        Commencing upon product release, capitalized software development costs are amortized to "cost of sales—software royalties and amortization" based on the ratio of current revenues to total projected revenues for the specific product, generally resulting in an amortization period of six months or less.

        Intellectual property license costs represent license fees paid to intellectual property rights holders for use of their trademarks, copyrights, software, technology, music or other intellectual property or proprietary rights in the development of our products. Depending upon the agreement with the rights holder, we may obtain the rights to use acquired intellectual property in multiple products over multiple years, or alternatively, for a single product. Prior to the related product's release, we expense, as part of "cost of sales—intellectual property licenses," capitalized intellectual property costs when we believe such amounts are not recoverable. Capitalized intellectual property costs for those products that are cancelled or abandoned are charged to product development expense in the period of cancellation.

        Commencing upon the related product's release, capitalized intellectual property license costs are amortized to "cost of sales—intellectual property licenses" based on the ratio of current revenues for the specific product to total projected revenues for all products in which the licensed property will be utilized. As intellectual property license contracts may extend for multiple years, the amortization of capitalized intellectual property license costs relating to such contracts may extend beyond one year.

        We evaluate the future recoverability of capitalized software development costs and intellectual property licenses on a quarterly basis. For products that have been released in prior periods, the primary evaluation criterion is actual title performance. For products that are scheduled to be released in future periods, recoverability is evaluated based on the expected performance of the specific products to which the costs relate or in which the licensed trademark or copyright is to be used. Criteria used to evaluate expected product performance include: historical performance of comparable products developed with comparable technology; orders for the product prior to its release; and, for any sequel product, estimated performance based on the performance of the product on which the sequel is based. Further, as many of our capitalized intellectual property licenses extend fo r multiple products over multiple years, we also assess the recoverability of capitalized intellectual property license costs based on certain qualitative factors, such as the success of other products and/or entertainment vehicles utilizing the intellectual property, whether there are any future planned theatrical releases or television series based on the intellectual property, and the rights holder's continued promotion and exploitation of the intellectual property.

        Significant management judgments and estimates are utilized in the assessment of the recoverability of capitalized costs. In evaluating the recoverability of capitalized costs, the assessment of expected product performance utilizes forecasted sales amounts and estimates of additional costs to be incurred. If revised forecasted or actual product sales are less than the original forecasted amounts utilized in the initial recoverability analysis, the net realizable value may be lower than originally estimated in any given quarter, which could result in an impairment charge. Material differences may result in the amount and timing of charges for any period if management makes different judgments or utilizes different estimates in evaluating these qualitative factors.

Inventories

        Inventories consist of materials (including manufacturing royalties paid to console manufacturers), labor and freight-in and are stated at the lower of cost (weighted average method) or market value.

Long-Lived Assets

        Property and Equipment.    Property and equipment are recorded at cost and depreciated on a straight-line basis over the shorter of the estimated useful lives or the lease term: buildings, 25 to 33 years; computer equipment, office furniture and other equipment, 2 to 5 years; leasehold improvements, the shorter of 5 years or the life of the lease. When assets are retired or disposed of, the cost and accumulated depreciation thereon are removed and any resulting gains or losses are included in the accompanying consolidated statements of operations.

        Goodwill and Other Indefinite-Lived Assets.    We account for goodwill using the provisions within ASC Topic 350. Under ASC Topic 350, goodwill is considered to have an indefinite life, and is carried at cost. Acquired trade names are assessed as indefinite lived assets as there are no foreseeable limits on the periods of time over which they are expected to contribute cash flows. Goodwill and acquired trade names are not amortized, but are subject to an impairment test annually and in between annual tests when events or circumstances indicate that the carrying value may not be recoverable. We perform our annual impairment testing at December 31.

        We have determined our reporting units based on the guidance within ASC Subtopic 350-20. As of December 31, 2009 and 2008, the Company's reporting units consisted of Activision, Blizzard, and Distribution. We test goodwill for possible impairment by first determining the fair value of the related reporting unit and comparing this value to the recorded net assets of the reporting unit, including goodwill. Fair value is determined using a combination of a discounted cash flow model and market comparable valuations of peer companies. The estimated fair values of each of our reporting units exceeded their carrying values by a range of approximately $0.1 billion to $5.9 billion as of December 31, 2009. The estimated fair values exceed their respective reporting units carrying values by a range of approximately 20% to 480% as of December&nb sp;31, 2009. As such, we have determined that no impairment has occurred at December 31, 2009 based upon a set of assumptions regarding discounted future cash flows, which represent our best estimate of future performance at this time. In determining the fair value of our reporting units, we assumed a discount rate between 11.5% and 13%.

        In completing our goodwill impairment analysis, we test the appropriateness of our reporting units' estimated fair value by reconciling the aggregate reporting units' fair values with our market capitalization. Our impairment analysis indicated that the aggregate fair values of our reporting units exceeded our December 31, 2009 market capitalization by approximately $3.9 billion or 26%.

        The fair value of an entity can be greater than its market capitalization for various reasons, one of which is the concept of control premium. A control premium is the amount that a buyer is willing to pay over the current market price of a company to acquire a controlling interest. Substantial value may arise from the ability to take advantages of synergies, such as the expected increase in cash flow resulting from cost savings and revenue enhancements, and other benefits could be achieved by controlling another entity. However, changes in our assumptions underlying our estimates of fair value, which will be a function of our future financial performance and changes in economic conditions, could result in future impairment charges.

        We test acquired trade names for possible impairment by using a discounted cash flow model to estimate fair value. As of December 31, 2009, the estimated fair values of each of our acquired trade names exceeded their carrying values by a range of approximately $4 million to $124 million, which exceeds their respective carrying values by a range of approximately 1% to 260%. As such, we have determined that no impairment has occurred at December 31, 2009 based upon a set of assumptions regarding discounted future cash flows, which represent our best estimate of future performance at this time. In determining the fair value of our trade names, we assumed a discount rate between 11.5% and 12%, and royalty saving rates of approximately 1%. A one percentage point increase in the discount rate would have reduced the indicated fair values of each of our acquired trade names by a range of approximately $22 million to $52 million, and would yield an impairment charge in the case of one of our trade names. Changes in our assumptions underlying our estimates of fair value, which will be a function of our future financial performance and changes in economic conditions, could result in future impairment charges.

        Amortizable Intangible Assets.    Intangible assets subject to amortization are carried at cost less accumulated amortization. Intangible assets subject to amortization are amortized over the estimated useful life in proportion to the economic benefits received.

        Management evaluates the recoverability of our identifiable intangible assets and other long-lived assets in accordance with FASB guidance within ASC Subtopic 360-10, which generally requires the assessment of these assets for recoverability when events or circumstances indicate a potential impairment exists. We considered certain events and circumstances in determining whether the carrying value of identifiable intangible assets and other long-lived assets may not be recoverable including, but not limited to: significant changes in performance relative to expected operating results; significant changes in the use of the assets; significant negative industry or economic trends; a significant decline in our stock price for a sustained period of time; and changes in our business strategy. In determining whether an impairment exists, we estimate the undiscounted cash flows to be generated from the use and ultimate disposition of these assets. If an impairment is indicated based on a comparison of the assets' carrying values and the undiscounted cash flows, the impairment loss is measured as the amount by which the carrying amount of the assets exceeds the fair value of the assets.

        During 2009, we recorded impairment charges of $24 million, $12 million and $373 million to license agreements, game engines and internally developed franchises intangible assets, respectively (see Note 12).

Revenue Recognition

• Product Sales

        We recognize revenue from the sale of our products upon the transfer of title and risk of loss to our customers, and once any performance obligations have been completed. Certain products are sold to customers with a street date (the earliest date these products may be sold by retailers). For these products we recognize revenue on the later of the street date or the sale date. Revenue from product sales is recognized after deducting the estimated allowance for returns and price protection.

        Some of our software products provide limited online features at no additional cost to the consumer. Generally, we consider such features to be incidental to the overall product offering and an inconsequential deliverable. Accordingly, we recognize revenue related to products containing these limited online features upon the transfer of title and risk of loss to our customer. In instances where online features or additional functionality is considered more than an inconsequential separate deliverable in addition to the software product, we take this into account when applying our revenue recognition policy. This evaluation is performed for each software product and any online transactions, such as electronic downloads of titles or product add-ons when it is released. When we determine that a software title contains online functionality that constitutes a more-than-inconsequ ential separate service deliverable in addition to the product, principally because of its importance to game play, we consider that our performance obligations for this title extend beyond the sale of the game. Vendor-specific objective evidence ("VSOE") of fair value does not exist for the online functionality, as we do not separately charge for this component of the title. As a result, we recognize all of the revenue from the sale of the title ratably over the estimated service period, which is estimated to begin the month after either the sale date or the street date of the title, whichever is later. In addition, we defer the costs of sales for the title (excluding intangible asset amortization) to match revenues. Cost of sales includes manufacturing costs, software royalties and amortization, and intellectual property licenses.

        We recognize World of Warcraft boxed product, expansion packs and other value added service revenues each with the related subscription service revenue ratably over the estimated service periods beginning upon activation of the software and delivery of the services. Revenues attributed to the sale of World of Warcraft boxed software and related expansion packs are classified as product sales and revenues attributable to subscription and other value added services are classified as subscription, licensing and other revenues.

        We currently estimate the service periods over which revenues are recognized range from a minimum of five months to a maximum of less than a year.

        With respect to online transactions, such as electronic downloads of titles or product add-ons that do not include a more-than-inconsequential separate service deliverable, revenue is recognized when the fee is paid by the online customer to purchase online content and the product is available for download. In addition, persuasive evidence of an arrangement must exist and collection of the related receivable must be probable.

        Sales incentives and other consideration given by us to our customers are considered adjustments of the selling price of our products, such as rebates and product placement fees, and are reflected as reductions to revenue. Sales incentives and other consideration that represent costs incurred by us for assets or services received, such as the appearance of our products in a customer's national circular ad, are reflected as sales and marketing expenses when the benefit from the sales incentive is separable from sales to the same customer and we can reasonably estimate the fair value of the benefit.

• Subscription Revenues

        Subscription revenues are derived from World of Warcraft, a game that is playable through Blizzard's servers on a subscription-only basis. After the first month of free usage that is included with the World of Warcraft boxed software, the World of Warcraft end user may enter into a subscription agreement for additional future access. Revenues associated with the sale of subscriptions via packaged software and prepaid subscription cards, as well as prepaid subscriptions sales, are deferred until the subscription service is activated by the consumer and recognized ratably over the subscription period. Revenue from Inter net gaming rooms in Asia is recognized upon usage of the time packages sold. Value added service revenues associated with subscriptions are recognized ratably over the estimated customer life.

• Licensing Revenues

        Third-party licensees in Russia, China and Taiwan distribute and host Blizzard's World of Warcraft game in their respective countries under license agreements with Blizzard. We receive royalties from the licensees as a result. We recognize these royalties as revenues based on the end users' activation of the underlying prepaid time, if all other performance obligations have been completed or based on usage by the end user when we have continuing service obligations. We recognize any upfront licensing fee received over the term of the contracts.

        With respect to license agreements that provide customers the right to make multiple copies in exchange for guaranteed amounts, revenue is generally recognized upon delivery of a master copy. Per copy royalties on sales that exceed the guarantee are recognized as earned. In addition, persuasive evidence of an arrangement must exist and collection of the related receivable must be probable.

• Breakage Revenues

        World of Warcraft boxed product sales and subscription revenues are recognized upon activation of the game. For certain products, activation has not occurred, which led us to analyze historical activation patterns over an extended period of time, to determine when the likelihood of activation ever occurring becomes remote. We recognize revenues from subscriptions that have not yet been activated, prepaid subscription cards, as well as prepaid subscription sales, when the likelihood of future activation occurring is remote (defined as "breakage revenues"). In 2008, we recognized breakage revenues for the first time since the initial launch of World of Warcraft. For the years ended December 31, 2 009 and 2008, we recorded $5 million and $6 million, respectively of breakage revenues from the sale of packaged software in product sales, and $8 million and $16 million, respectively of prepaid and subscription breakage revenues in subscription, licensing and other revenues in the consolidated statements of operations.

• Other Revenues

        Other revenues primarily include value added service sales of non-software related products. It includes licensing activity of intellectual property other than software to third-parties. Revenue is recorded upon receipt of licensee statements, or upon the receipt of cash, provided the license period has begun.

Allowances for Returns, Price Protection, Doubtful Accounts, and Inventory Obsolescence

        We closely monitor and analyze the historical performance of our various titles, the performance of products released by other publishers, and the anticipated timing of other releases to assess future demand of current and upcoming titles. Initial volumes shipped upon title launch and subsequent reorders are evaluated with the goal of ensuring that quantities are sufficient to meet the demand from the retail markets, but at the same time are controlled to prevent excess inventory in the channel. We benchmark units to be shipped to our customers using historical and industry data.

        We may permit product returns from, or grant price protection to, our customers under certain conditions. In general, price protection refers to the circumstances in which we elect to decrease the wholesale price of a product by a certain amount and, when granted and applicable, allows customers a credit against amounts owed by such customers to us with respect to open and/or future invoices. The conditions our customers must meet to be granted the right to return products or price protection include, among other things, compliance with applicable trading and payment terms, and consistent return of inventory and delivery of sell-through reports to us. We may also consider other factors, including the facilitation of slow-moving inventory and other market factors. Management must make estimates of potential future product returns and price protection related to current perio d product revenue. We estimate the amount of future returns and price protection for current period product revenue utilizing historical experience and information regarding inventory levels and the demand and acceptance of our products by the end consumer. The following factors are used to estimate the amount of future returns and price protection for a particular title: historical performance of titles in similar genres; historical performance of the hardware platform; historical performance of the franchise; console hardware life cycle; sales force and retail customer feedback; industry pricing; weeks of on-hand retail channel inventory; absolute quantity of on-hand retail channel inventory; our warehouse on-hand inventory levels; the title's recent sell-through history (if available); marketing trade programs; and competing titles. The relative importance of these factors varies among titles depending upon, among other items, genre, platform, seasonality, and sales strategy. Significant management judgme nts and estimates must be made and used in connection with establishing the allowance for returns and price protection in any accounting period. Based upon historical experience, we believe that our estimates are reasonable. However, actual returns and price protection could vary materially from our allowance estimates due to a number of reasons including, among others, a lack of consumer acceptance of a title, the release in the same period of a similarly themed title by a competitor, or technological obsolescence due to the emergence of new hardware platforms. Material differences may result in the amount and timing of our revenue for any period if factors or market conditions change or if management makes different judgments or utilizes different estimates in determining the allowances for returns and price protection. For example, a 1% change in our December 31, 2009 allowance for returns and price protection would impact net revenues by approximately $3 million.

        Similarly, management must make estimates of the uncollectibility of our accounts receivable. In estimating the allowance for doubtful accounts, we analyze the age of current outstanding account balances, historical bad debts, customer concentrations, customer creditworthiness, current economic trends, and changes in our customers' payment terms and their economic condition, as well as whether we can obtain sufficient credit insurance. Any significant changes in any of these criteria would affect management's estimates in establishing our allowance for doubtful accounts.

        We regularly review inventory quantities on-hand and in the retail channel. We write down inventory based on excess or obsolete inventories determined primarily by future anticipated demand for our products. Inventory write-downs are measured as the difference between the cost of the inventory and net realizable value, based upon assumptions about future demand, which are inherently difficult to assess. At the point of a loss recognition, a new, lower cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established basis.

Shipping and Handling

        Shipping and handling costs, which consist primarily of packaging and transportation charges incurred to move finished goods to customers, are included in "cost of sales—product costs."

Advertising Expenses

        We expense advertising as incurred, except for production costs associated with media advertising which are deferred and charged to expense the first time the related ad is run. Advertising expenses for the years ended December 31, 2009, 2008, and 2007 were $366 million, $241 million, and $73 million, respectively, and are included in sales and marketing expense in the consolidated statements of operations.

Income Taxes

        We account for income taxes using ASC Topic 740, Income Taxes. Under ASC Topic 740, income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

4. Investment and other income (loss), net

        Investment and other income (loss), net is comprised of the following (amounts in millions):