Ask HN: Money as a motivation for keeping an app installed?

I am working on a start-up with a bunch of people and wanted feedback on some of the things.

Context: Indian Market

There seems to be no good platform which connects companies/startups to customers for surveys and feedback especially if the company is concerned about feedback from a certain section of users i.e. based on age or location.

My Questions:

1. Would you keep a simple app on your phone/tablet which pushes surveys and feedback to you. It would reward you with some nominal amount of money. ( what would be that amount for you ? )

2. I know these kind of money making apps go viral in their initial phase. What do you guys think of the long term sustainability of such an app.