management to make judgments, assumptions, and estimates that affect the amounts reported in its Consolidated Financial Statements and accompanying notes. Note 1 “Summary of Significant Accounting Policies” of Notes to Consolidated Financial Statements in this Form 10-K describes the significant accounting policies and methods used in the preparation of the Company’s Consolidated Financial Statements. Management bases its estimates on historical experience and on various other assumptions it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results may differ from these estimates and such differences may be material. 

Management believes the Company’s critical accounting policies and estimates are those related to revenue recognition, allowance for doubtful accounts, inventory valuation and inventory purchase commitments, warranty costs, stock-based compensation, income taxes, and legal and other contingencies. Management considers these policies critical because they are both important to the portrayal of the Company’s financial condition and operating results, and they require management to make judgments and estimates about inherently uncertain matters. The Company’s senior management has reviewed these critical accounting policies and related disclosures with the Audit and Finance Committee of the Company’s Board of Directors. 

Revenue Recognition 

Net sales consist primarily of revenue from the sale of hardware, software, music products, digital content, peripherals, and service and support contracts. The Company recognizes revenue for software products (operating system software and applications software), or any product that is considered to be software-related, in accordance with the guidance in Emerging Issues Task Force (“EITF”) No. 03-5, Applicability of AICPA Statement of Position 97-2 to Non-software Deliverables in an Arrangement Containing More-Than-Incidental Software , (e.g., Mac computers, iPod portable digital music players and iPhone) pursuant to American Institute of Certified Public Accountants (“AICPA”) Statement of Position (“SOP”) No. 97-2, Software Revenue Recognition , as amended. For products that are not software or software-related, (e.g., digital content sold on the iTunes Store and certain Mac, iPod and iPhone supplies and accessories), the Company recognizes revenue pursuant to the Securities and Exchange Commission (“SEC”) Staff Accounting Bulletin (“SAB”) No. 104, Revenue Recognition.

The Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred, the sales price is fixed or determinable, and collection is probable. Product is considered delivered to the customer once it has been shipped and title and risk of loss have been transferred. For most of the Company’s product sales, these criteria are met at the time the product is shipped. For online sales to individuals, for some sales to education customers in the U.S., and for certain other sales, the Company defers revenue until the customer receives the product because the Company retains a