Another example of power law - this is entirely uninteresting

Yes, the App Store, which has seen a billion - a billion! - downloads since it opened in June. Using the calculation of paid v free downloads (which are reckoned to be in the 1/15 to 1/40 range, and the estimated average cost of an app (about $2.65, he reckons, which fits with Silicon Alley Insider's own analysis, which found that the average paid-for app in the top 100 sellers - which is where pretty much all the action is - sales follow a power law, falling off radically from the top 10 to the next, and from the top 100 to the many others), Liew calculated that Apple has, with its 30% rakeoff, pulled in between $49.7m (at 1:15) and $19.4m in those nine months. Those numbers, of course, don't include the costs of running the store, which will knock at least a few million off - you've got servers to run, and people approving and disapproving apps.

This article explains how apple's sales (now qualifying it as a software company!) in terms of top apps mimic the power law!!

http://www.guardian.co.uk/technology/2009/may/15/apple-app-store-software-hardware