As of July 26th, it looks likes promo codes have been allowed again for 17+ apps.
http://www.tuaw.com/2009/07/26/update-promo-codes-are-now-al...
4 karma · joined July 21, 2009
http://www.tuaw.com/2009/07/26/update-promo-codes-are-now-al...
But one benefit I can see is that these switches increase the target area, which I've always found to be somewhat small with checkboxes and radio buttons...
http://www.techcrunch.com/2009/07/07/amazon-killing-mobile-a...