I asked them a follow-up question to judge what made them use foursquare on a daily basis. To my surprise, all users mentioned acquiring more badges as one of their main motives. Some also mentioned the Leaderboard.
This prompted me to further ask the users whether badges and leaderboards would motivate them to use an online radio. Although most of the responses I got were quantitative, I did get a lot of qualitative feedback as well. One of the users also added that he would love to be rated by fellow users (instead of the computer). This encouraged me to ask them about the upvotes, etc..
How would you recommend me asking the users about new features?