Graham Spencer takes you on a behind-the-scenes guided tour through the App Store’s Top Grossing chart.

From the wrap-up:

If you regularly browse the App Store’s Top Charts most of these results would likely serve to confirm what you had already assumed. Most obviously, if you were to randomly pick an app from the Top 200 Grossing charts, chances are extremely high that you would pick a free app with IAPs and it would most likely be a game. But what is particularly suprising is the degree to which free apps with IAP dominate the charts with essentially no paid apps or no apps without IAPs.

Some fascinating numbers here.