I would have to agree, the problem is when you have to self measure a potential projects earnings before it comes into a large circulation.

I think it would be very easy to over/under estimate a projects worth, personally I would think that a percentage of profits over a certain period of time plus a smaller lump sum would be ideal for me.

I am a little new to this game but I would assume it would also increase my motivation to see a project come to fruition if I had a more longterm stake in it.