Between apps and the Web, David Gill, VP, mobile media and marketing for the Nielsen Company, said people are spending 55% to 60% of their time on apps because the mobile Web experience is still less user-friendly. He also pointed out that the top 50 apps in the Android Market account for 60% of usage, again reinforcing how critical it is for publishers to land in that top group of titles in Android or the App Store. The good news, from a developer standpoint, is that the top 50 titles tends to turn over fairly rapidly from month to month.