I was completely amazed after listening and reading this blog post. It's a great post explaining on how a digital product, Parrotsecrets, came about. The practical steps you should take if your gonna release your own product. And this proves it doesn't have to be in the IM niche to make money! Really it boils down to this - Find a MARKET/NICHE that has money to spend, provide a SOLUTION for their problem.
Check out the post here: I, Cringely » Blog Archive » Parrot Secrets - Cringely on technology