That Instagram thing has been annoying the shit out of me too. I get a fairly consistent 2 new followers per week, but in the last year my total followers has only gone up by about 10. So people are following me, then hoping for a follow back, and then unfollowing me. So now I only follow people who have a follower:following ratio approaching 1 (or they have outstanding content). If they have tonnes of followers and very few they follow, unless their work is really good, I ignore them. They are likely the follow for follow, then unfollow, wankers.