The Sports Illustrated (NYSE: TWX) swimsuit issue’s Midas touch continues: three weeks after launch, SI has delivered nearly 570,000 downloads of its ad-supported “freemium” Sports Illustrated Swimsuit 2010 app—and, according to SI.com Managing Editor Paul Fichtenbaum, converted roughly 10 percent to paid users at $1.99 a pop. For those of you keeping score at home, that’s about $113,430 in revenue for 57,000 upgrades. That compares with about 30,000 paid downloads for the premium-only Swimsuit 2009.

Ten percent is good but you’d almost think the number would be higher. For their $1.99 upgrade to Swimsuit 2010 Premium, users get nearly 50 additional videos, including some exclusive footage, and much more of the coverage from the magazine (the Olympians, etc.) Granted, it’s a much smaller format than the magazine; it’s also much more portable. Maybe if SI sold a Boss/Significant Other version that showed up as something else…

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