Edit: Games also tend to be the biggest draws since people get cool tangible rewards.
Would having a Dr. drone give you an in-home visit be a decent reward? (Let's call this marketing research )
No, but then again I'm probably not your target audience. I go to the doctor once every couple of years and I've had to argue with doctors before because i know my body so I wouldn't trust a drone to get it right.
It's a reward though, so that's something.
There are people that will give because an idea is cool or out of the goodness of their hearts or because the project is for something they're genuinely interested in. My backer history informs me that i"m not one of those people.
Edit again: Except for Reading Rainbow, they got my money just because.