I've seen several strategies like this to improve startups/sideprojects Keep statistics on people who have: signed up but not set up your product <- Contact these to see if they need help setting up signed up and set up your product but stopped using it <-Contact these to find out what's wrong with your product

The best way to do this is to send a personal email to the users. You should be able to get some real feedback and if you're responsive to their suggestions get some customers for life