I forgot to mention that about the same time that Blogger upgraded my account to Ad-Free, the Gmail team replied to my invitation refund request. It turns out I could simply forward the copy of the invitation from my Sent folder to the new recipient of the invitation. Since Google seems to be giving away invitations like mad these days, I figured I'd just give my last one to a guy on IRC who really wanted it. I needed to get rid of it somewhat quickly anyway, since (because it was already sent once) it would expire in less than three weeks. Anyway, now I'm out of invites for real.