There are two articles you might find interesting. There May Be 50,000 Apps For The iPhone, But Only A Select Few Become Popular Report: iPhone Applications Are Getting Cheaper Also here are some PDF reports Apple App Store Report US May 09 Admob mobile metrics report May 2009
Not a huge surprise here. Ever heard of the Pareto Principle? Though I didn't have any data until I read this article, it wasn't much of a surprise. This is the reason I havn't taken the plunge into app dev. It is a tough struggle to make any money; and with high end production companies like Gameloft selling their top tier titles at $.99, getting noticed through this is even tougher!
