FAB, that's a good theory. Clearly they instituted the 25k requirement for the lounges in order to press people to play past the 15k mark, but they probably found that there was such a wide gap between 25k and 150k that a lot of people really cut their play down after that.

I wouldn't be surprised if they simply make Diamond 25k next year.

BTW I was told last year that you can only tier match once. However, I believe the Founders Card thing works continuously. I'm probably just going to re-earn my Diamond in January.