Join a new fandom, and get followers in the watchers list due to that you started to draw fanarts of it. Everybody loves your art. BUT in many cases: A 15 minutes doodle of a popular character could have more succes than a amazing pic of a minor character of the same serie done in 3 hours or more.
• 15 minutes doodle + popular character + in any or 2 groups max (and it rains invitations to submit to more groups!) --> 150 favs in 5 hours -or less-.
• 3 hours + awesome pic + minor character --> 16 favs in 2 days -hopefully!-.
Some of your active watchers changed their fandom and taste, and they "disappear" suddenly, only few of them keep commenting your art (still from the fandom you joined in the first point), due to they really like your style or love you and don't care about if it's fanart or not.
Now the inverse: You change the fandom, and these who followed you because of your other fandom's fanarts, still fave or do requests about them, others directly stop watching you.
Something similar, but you don't join other fandom: You start to draw your own characters. Just a few of watchers comment/follow it... Others keep comparing them with any character of a famous manga... Others think they are fancharacters and not OCs.
You draw a really minor character, but some watchers think it's an OC or a Fancharacter , since they only know or remember the mains or popular character (yeah, it happened to me )
Some fans want to kill you because you drew their favourite character in a yaoi/yuri/hetero/with a pairing they don't like/etc. Others want to make a monument of you because you drew their fav couple, etc.
You draw a character from this certain fandom, people who love this character appear and suddenly love you!! Yay! ♥ But if you don't draw this character, these fans, never appear...*^*
Some of the comments you receive are a squeals XD.
The quantity of comments you receive is completely unproportional to the faves you receive (example: 2 comments, 118 faves, submitted 3 weeks ago).
Some fanartists when they discover their "karma" become victims of fright (?) and abandon their accounts, creating a new one... or directly leave the site. (In my case, I had too many identities all along the eight years I've been on dA ). Some watchers go crazy and decide to unwatch you (or directly they don't find you until years later). Sometimes, the fanartist decides to come back to their first account (if it wasn't deactivate).
Something good, now: Some people start to like some characters/couple/series/etc. because they saw your art! (That makes me proud of being fanartist ) xD.
Sorry it became too long .