Table of Contents

Operating Expenses

Information about operating expenses with and without stock-based compensation is as follows (in millions):

Operating expenses without stock-based compensation are non-GAAP financial measures. See “Non-GAAP Financial Measures” and Item 8 of Part I, “Financial Statements and Supplementary Data—Note 1—Description of Business and Accounting Policies—Stock-Based Compensation.”

Cost of Sales

Cost of sales consists of the purchase price of consumer products and digital content where we are the seller of record, including Prime Instant Video, inbound and outbound shipping charges, and packaging supplies. Shipping charges to receive products from our suppliers are included in our inventory, and recognized as cost of sales upon sale of products to our customers.

The increase in cost of sales in absolute dollars in 2012, 2011, and 2010 compared to the comparable prior year periods, is primarily due to increased product, digital content, and shipping costs resulting from increased sales, as well as from expansion of digital offerings.

Consolidated gross profit and gross margin for each of the periods presented were as follows:

Gross margin increased in 2012, compared to the comparable prior year periods, primarily due to services sales increasing as a percentage of total sales. We believe that income from operations is a more meaningful measure than gross profit and gross margin due to the diversity of our product categories and services.

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