It'll probably slow growth in a good way. It's really a pretty low bar for anyone who's even half serious about doing recurring billing. It seems like a pretty good way to cap who you're providing support to, and it's a small enough monthly fee that people won't even think twice before paying it... assuming they're half serious, again.
It's a big bar if you just want to test out the service to see if it actually converts better than whatever solution you are currently using. Because anyone who is half serious will have other solutions he is already using.
