|AMAZON COM INC filed this Form 10-K on 01/30/2013|
The following table shows the calculation of diluted shares (in millions):
Cash and Cash Equivalents
We classify all highly liquid instruments with an original maturity of three months or less at the time of purchase as cash equivalents.
Inventories, consisting of products available for sale, are primarily accounted for using the FIFO method, and are valued at the lower of cost or market value. This valuation requires us to make judgments, based on currently-available information, about the likely method of disposition, such as through sales to individual customers, returns to product vendors, or liquidations, and expected recoverable values of each disposition category.
We provide Fulfillment by Amazon services in connection with certain of our sellers programs. Third-party sellers maintain ownership of their inventory, regardless of whether fulfillment is provided by us or the third-party sellers, and therefore these products are not included in our inventories.
Accounts Receivable, Net, and Other
Included in Accounts receivable, net and other on our consolidated balance sheets are amounts primarily related to vendor and customer receivables. At December 31, 2012 and 2011, vendor receivables, net, were $1.1 billion and $934 million, and customer receivables, net, were $1.5 billion and $1.2 billion.
Allowance for Doubtful Accounts
We estimate losses on receivables based on known troubled accounts and historical experience of losses incurred. Receivables are considered impaired and written-off when it is probable that all contractual payments due will not be collected in accordance with the terms of the agreement. The allowance for doubtful accounts was $116 million and $82 million at December 31, 2012 and 2011.
Internal-use Software and Website Development
Costs incurred to develop software for internal use and our websites are capitalized and amortized over the estimated useful life of the software. Costs related to design or maintenance of internal-use software and website development are expensed as incurred. For the years ended 2012, 2011, and 2010, we capitalized $454 million (including $74 million of stock-based compensation), $307 million (including $51 million of stock-based compensation), and $213 million (including $38 million of stock-based compensation) of costs associated with internal-use software and website development. Amortization of previously capitalized amounts was $327 million, $236 million, and $184 million for 2012, 2011, and 2010.