The most accurate article iv read in a long time!
I have Ginabot notify me when i get new followers - amazing how many people follow like 15k people, they never see your post!
I have nearly 500 followers and i think i probably only have interactions with maybe 10 percent of them. Alot are probably inactive aswell.
Im very selective with who i follow and often go through my list and unfollow those who are inactive or for whatever reason i dont interact with. Its amazing your 'following'list can get big quickly if you dont keep an eye on it