The question will depend on the project development phase you are currently in. I assume that you're on the real beginning - verifying the assumptions about the customer's problem, right? So, you need to identify the actual target group, provide them some more information about the problem you're aiming to solve and ask about details of the problem - not the solution (as some of the questions in you survey are). So, people who have this problem will provide you with info without any inncentives. Those who don't feel any problem - will quit but that's ok coz they're not your target group. So the challenge is not to get lots of data, but data from small, but accurate sample. You can check how we used this approach on http://www.nanokoan.com If you're the leader of the project don't hesitate to fill the survey - you're our target group :)