You can ask and ask and ask and ask but at the end of the day the ONLY way you are going to know if an idea is going to make you money is to try it.
I seriously believe "asking" is an epidemic in most businesses and very much so in IM. Too many "askers" and not enough "doers".
Check out this 20 minute video of Seth Godin making some good points to help you get out of the "asker" state of mind. Seth Godin on Failing Until You Succeed - YouTube
I know personally I can fall victim to this often if I don't keep it in check. It really is worth getting it in "check".