and 2011, compared to the comparable prior year periods, is primarily due to increased spending on online marketing channels, such as our sponsored search programs and our Associates program, payroll and related expenses, and television advertising. 

While costs associated with Amazon Prime memberships and other shipping offers are not included in marketing expense, we view these offers as effective worldwide marketing tools, and intend to continue offering them indefinitely. 

Technology and Content 

We seek to efficiently invest in several areas of technology and content such as technology infrastructure, including AWS, expansion of new and existing product categories and offerings, and initiatives to expand our ecosystem of digital products and services, as well as in technology infrastructure so we may continue to enhance the customer experience and improve our process efficiency. We expect spending in technology and content to increase over time as we continue to add employees and technology infrastructure. 

The increase in technology and content costs in absolute dollars in 2013 , 2012 , and 2011 , compared to the comparable prior year periods, is primarily due to increases in payroll and related expenses, including those associated with our initiatives to expand our ecosystem of digital products and services, and increased spending on technology infrastructure, including AWS. We expect these trends to continue over time as we invest in these areas by increasing payroll and related expenses and adding technology infrastructure. 

For 2013, 2012, and 2011, we capitalized $581 million (including $87 million of stock-based compensation), $454 million (including $74 million of stock-based compensation), and $307 million (including $51 million of stock-based compensation) of costs associated with internal-use software and website development. Amortization of previously capitalized amounts was $451 million, $327 million, and $236 million for 2013 , 2012 , and 2011. A majority of our technology costs are incurred in the U.S., most of which are allocated to our North America segment. Infrastructure, other technology, and operating costs incurred to support AWS are included in technology and content. 

General and Administrative 

The increase in general and administrative costs in absolute dollars in 2013 , 2012 , and 2011 , compared to the comparable prior year periods, is primarily due to increases in payroll and related expenses. 

Stock-Based Compensation 

Stock-based compensation was $1.1 billion, $833 million, and $557 million during 2013, 2012, and 2011. The increase in 2013, 2012, and 2011, compared to the comparable prior year periods, is primarily due to an increase in the number of stock-based compensation awards granted to existing and new employees. 

Other Operating Expense (Income)

Other operating expense (income), net was $114 million, $159 million, and $154 million during 2013, 2012, and 2011, and was primarily related to the amortization of intangible assets, partially offset by the settlement of certain unclaimed property and indemnification claims in Q3 2013. 

Income from Operations 

For the reasons discussed above,