Of the three invitations I was given from Gmail, I sent one to a brother and I planned to send one to a guy I know online. After Gmail gave the invitations, the service experienced a notable slowdown, at least for me. It often took a dozen or so attempts to successfully navigate to another section. I should have known that this could result in a problem during the invitation process. When I went to send my second invitation, it took quite a long time to process it, and when it finally displayed the page saying that the invitation was sent, it said I had 0 invitations remaining. Even though I only pressed the Send button once, it took two of my invitations away. The guy I sent it to shortly thereafter told me that he receieved two separate invitations from me. I told him not to do anything for a day or so until Gmail starts running smoothly again, and only to accept one of the invitations and to ignore the other, in hopes that unanswered invitations might be refunded after some time. But at the moment, I suppose I'll just assume that I'm out of invitations. It's a good thing that I hadn't yet made any plans for my last invitation.