@Marvin - wow, that's living the dream right there!
I started a week ago here on Tapastic, and one of my comics has 20 subs, the other has 30.
I'm really intregued by the fact that my older black and white comic is "winning" so far! I think the thumbnail is grabbing more people because its got a mysterious monster in it, rather than an old lady (I guess old ladies are boring
I'll have to try to work out how to fix that.)
Over on my main site at ComicFury my first comic started to build more of a following after it had ended than when it was currently updating, so when I started posting my new comic it gained a lot of subs very quickly just because people knew me/liked the other comic. I know a couple of people were really baffled that I had so many subs so quickly, I had to reassure people, nooo I've worked for a year to build that readership!