I wonder if they are letting the smaller apps (like Untappd) be their check-in frontend and they basically just aggregate up all the locations the people have "

I wonder if they are letting the smaller apps (like Untappd) be their check-in frontend and they basically just aggregate up all the locations the people have "checked-in". With Untappd, to create a new location, you have to download Foursquare and create it so it keeps users creating new venues and you immediately have a somewhat genre.