segments: North America and International. We present our segment information along the same lines that our chief executive reviews our operating results in assessing performance and allocating resources. 

Net Sales and Gross Profit 

Revenue increased 28%, 29%, and 39% in 2009, 2008, and 2007. Changes in currency exchange rates positively (negatively) affected net sales by $(182) million, $127 million, and $399 million for 2009, 2008, and 2007. For a discussion of the effect on revenue growth of exchange rates, see “Effect of Exchange Rates” below. 

The North America revenue growth rate was 25%, 26%, and 38% in 2009, 2008, and 2007. The increase in revenue in each year primarily reflects increased unit sales driven largely by our continued efforts to reduce prices for our customers, including from our free shipping offers and Amazon Prime, and by increased in-stock inventory availability and increased selection of product offerings, as well as a larger base of sales in faster growing categories such as electronics and other general merchandise, increased in-stock inventory availability, and increased selection of product offerings. 

The International revenue growth rate was 31%, 33%, and 39% in 2009, 2008, and 2007. The increase in revenue in each year primarily reflects increased unit sales driven largely by our continued efforts to reduce prices for our customers, including from our free shipping offers, and Amazon Prime, and by increased in-stock inventory availability and increased selection of product offerings, as well as a larger base of sales in faster growing categories such as electronics and other general merchandise, increased in-stock inventory availability, and increased selection of product offerings. Additionally, changes in currency exchange rates positively (negatively) affected International net sales by $(174) million, $131 million, and $390 million in 2009, 2008, and 2007. 

We expect that, over time, our International segment will represent 50% or more of our consolidated net sales. Additionally, as we continue to offer increased selection, lower prices, and additional product lines within our electronics and other general merchandise category, we expect to see the relative mix of sales from this category increase. See “Supplemental Information” below. 

The increase in gross profit in absolute terms during 2009, compared to 2008 and 2007, corresponds with increases in sales, offset by lower prices for customers including from free shipping offers and Amazon Prime. Generally, our gross margins fluctuate based on several factors, including our product, service, and geographic mix of sales; sales volumes by other sellers; changes in vendor pricing, including the extent to which we receive discounts and allowances; lowering prices for customers, including from competitive pricing decisions; improvements in product sourcing and inventory management; and the extent to which our customers accept our free shipping and Amazon Prime offers. Such free shipping and Amazon Prime offers reduce shipping revenue and reduce our gross margins on retail sales. We view our shipping offers as an effective worldwide marketing tool and