I do want to add a few points to his data: 1) The average "Social Networking" price of the top 50 in the UK store is (in US tiers) $2.72, not $0.99. Similarly,

I do want to add a few points to his data: 1) The average "Social Networking" price of the top 50 in the UK store is (in US tiers) $2.72, not $0.99. Similarly, the median is $1.99. Only 22 / 50 apps are priced $0.99. 2) The #1 "Social Networking" app has position #34 in the overall top 50 list. Clearly, social networking has a lot less market share than Entertainment or Games. 3) You shouldn't look at just the US store. Rankings can differ a lot between countries. Your app might be #34 in the US, but might not even be in the top 100 in other countries