the Middle East and Africa. The Retail segment operates Apple-owned retail stores in the U.S., Canada, Japan, the U.K. and Italy. Each reportable geographic operating segment and the Retail operating segment provide similar hardware and software products and similar services. During 2007, the Company revised the way it measures the Retail Segment's operating results to a manner that is generally consistent with the Company's other operating segments. Prior period results have been reclassified to reflect this change to the Retail Segment's operating results along with the corresponding offsets to the other operating segments. Further information regarding the Company's operating segments may be found in Note 9, 

 "Segment Information and Geographic Data" in Notes to Consolidated Financial Statements of this Form 10-K. 

Americas 

During 2007, net sales in the Americas segment increased $2.2 billion, or 23%, compared to 2006. The main sources of this growth were Mac portable products, iMacs, iPods, and the sales of third-party content from the iTunes Store. Sales of Mac portable products increased due to the popularity of the MacBook, introduced in May 2006 and updated in May 2007, as well as the MacBook Pro, introduced in January 2006 and updated in June 2007. Sales of iMacs grew due to a shift in desktop product mix away from the Mac mini and discontinued eMac as well as the strong reception of the new iMac introduced in August 2007. Sales of iPods grew due to increased demand for the iPod nano and iPod shuffle and the introduction of the iPod touch in September 2007. The Company believes that the growth in iTunes Store sales was the result of heightened consumer interest in downloading digital content and the expansion of third-party audio and video content available for sale via the iTunes Store. During 2007, the Americas segment represented 48% of the Company's total net sales as compared to 49% in the same period of 2006. During 2007, U.S. education channel net sales and Mac unit sales increased by 14% and 18%, respectively, compared to 2006. Net sales from the higher education market grew 17% during 2007 compared to 2006, while net sales in the K-12 market grew 10% during the same period. 

During 2006, net sales in the Americas segment increased $2.8 billion, or 41%, compared to 2005. The primary contributors to this increase were iPods, other music related products and services, Mac portable systems, and APP. Sales of iPods increased primarily due to the introduction of the updated iPod with video-playing capabilities in October 2005 (now referred to as iPod classic) and the iPod nano during September 2005. The increase in other music related products and services was due to increases in sales of Apple-branded and third-party iPod accessories and sales from the iTunes Store. The increase in sales of Mac portable systems in the Americas was due to strong sales of the MacBook and MacBook Pro during 2006. The overall increase in net sales was partially offset by a decline in net sales of desktops, displays, and Mac OS X. The decrease in desktop products and displays net sales reflects the overall shift in product mix toward portable