This is ancillary to the effort, but I think it's interesting. So here goes, I am not certain about skewing the pool less than more prize-based incentives -- as opposed to somewhat evenly. However, I definitely agree with the implied concept that the resulting pool will yield more carefully completed (and hence more useful/accurate) survey results.

And before we deviate too far from the core point of the thread, I'll simply echo my earlier sentiment regarding the act of quitting for a startup: great job so far, and good luck moving forward.