You see this question all of the time from new artists, there's a rush to reach a certain number or a certain status. All I can say is you are focusing on the wrong thing. And for those saying webcomics is "new" territory - no. The first webcomics began posting in the mid-90's kids - close to 15 years ago. New it's not. But things do change.
You want followers? Make something great. That's the answer, and I know, it's a sucky answer - but it's true. Your time should be focused on making something that resonates with people. Making yourself a better artist every day. Those are the things that will make you a successful artist. And by successful I do NOT mean financial success.
It can take years to build a following, so you need to settle in and produce quality work for the long haul. There's no magic bullet, no facebook, tumblr or dA post you can make that will make you a success. Even a viral post on Reddit will only give you temporary notice.
Make something great. Finish it. Repeat. Keep doing it.
For myself, I've been making comics 6+ years. I did Marooned from 2008-2013, and successfully Kickstarted it in Aug '13. I'm on my second graphic novel. I've done handfuls of other short stories and comics.
I began posting some stuff here a couple weeks ago. In total of everything I've posted, I have around 250 followers. Tapastic has been nice because it has helped me reach new people. One of the hardest things to do is get new audiences to look at your work. The stuff I am posting has been finished for a while, so it has been easy for me to post a lot of new material quickly. Something you can't do as a new artist - again, put in the time.
TLDR; TIME is the currency you pay as an artist to gain followers.
