Have you observed the way Google maps asks for info about local joints and places? They word it in such a manner that it sounds like you are helping others to make an informed decision along the lines of “Give us more info to help others”. What they are doing in effect is appealing to the altruism in all of us to generate more info to make their product better.
I think this is a great way to ask for more data in this world of user generated content. Instead of asking to review a restaurant how about wording it as “Review this place so that others can discover great food”. Instead of asking people to rate your app how about saying “Help your friends discover the app on playstore, rate us”. It would be interesting to A/B test this and see the result.