This is a super interesting thread and question -- I always struggled with this as a game producer, if you're going about this fully indie, it's pretty hardcore and rough. The chances of getting a run away success is quite slim.
However, there's lots of great fun ideas out there, which is why they shouldn't be thrown away but actually sold off, so I built a platform to help this happen -> indieacquire.com which basically lets indies sell their game / ip / idea etc and get some cash for the work that they have done which is pretty neat.
Just soft launched, so it would be good to get some feedback from anyone that's been trying to make some money from their games or haven't been able to and this might be a lifeline.
T