Asking paying customers for this is basically a kickstarter. People get what they pay for. And if they do pay, that is evidence, that it literally does pay out.
That being said, adding things in a game that do not fit the overal (planned) setting of the game might harm that setting. And asking only very few people will give unreliable results.
yup i've seen thousands of devs in early stage of development do this and before the game has even started it's beeing abandoned. devs who employ tactics like this very quickly realize it's no longer their game but the 5 to 10 people people paying 5 bucks a month's game. stick with your vision. don't get greedy and if you have a good product people will support you!
