There are multiple articles that I have read that do not paint a pretty picture. AllAboutSymbian has started a multi-part series on how to monetize your apps. Sure it may earn you some change if some people bother to click Buy and check it out, but it does not seem like it will make you big money with only a few exceptions.
Short answer: don't quit your day job just yet.
The Model M is not for the faint of heart. You either like them or hate them.
Gerbils unite! Fold for UnitedGerbilNation, team 2630.