While I can say that I don't think my subscribers are "fake" (that is somewhat of a harsh word to use), I do think a lot of my subscriber/watchers/followers are "inactive" though. There is just that slight different between fake and inactive to me. I have over 1k watchers on DA and only a hundred or less ever votes in my pool, only a handful of people that I consider FRIENDS ever comment on my stuffs. I'm very used to this so I don't think it's that big of a deal. Although I do know some people tend to get very paranoid when more than 3/4 of their watchers are inactive and rather abandon the account to make a new one than sticking around with "dead" watchers.
On Tapastic, I only have around 100+ subs. Not a lot people have bothered to leave a comment on my comic. (Only a few) but that makes every little comments I get a big motivational boost and get me bumped to work more on the comic.
Just try to stay positive really, there is nothing people can gain from being a "fake" subscriber. Inactive, maybe, shy, perhaps. Or purely just lazy to leave a comment, like me. I'M SORRY I LOVE YOU ALL, EVERY WEBCOMIC I SUB'ED TOO OUT THERE