First off, nice name! (How do you memorize that? I respect you!)
Yes, I do get more viewers over subscribers. Quite positive 99.99% of all series does. Except maybe that one series one person viewed and subscribed. I wouldn't worry about it, it's natural. I don't know if Tapastic counts viewers w/o an account, but they probably do.
It's kind of hard to tell how good/bad a comic is solely on one picture/link/thumbnail alone. If the user decides to check it out and doesn't enjoy what they see, they turn around. And you get stuck with a viewer. Just a viewer.
EDIT: Also, it's just a few days. Give it some time