Someone who made several games I'm interested in will get a follow from me, since they're likely to make more. Someone whose taste in games I know will also get a follow because they might rate and collect games that are also to my liking. Friends, too, because friends.
Of course, sometimes it turns out to be a wrong move. If someone floods my feed with stuff I don't care about, well, it's just as easy to unfollow them again. But that's just life.