Okay ... we've listened to our users on this one (other people said similar things :-), and now http://micropledge.com/ is as open as it'll ever be.

I know what you mean about not hearing back about invites -- we aimed to reply to each one with an invite code ASAP. We debated the invite issue. Our thought was that we don't want too much happening too fast in case there are problems. But having the invites caused more problems, I think.

So my advice: don't do invites -- they complicate things and confuse people. Just hold back on the PR if you're worried.