D'oh! I thought it was one of those "monthly subscription rolls over forever until you decide to cancel" deals.
Sorry for the confusion.
To try to stop this from being a complete waste of everyone's time, I guess I might suggest automagically sending a private message to someone when their account expires, explaining what's happening, thanking them for their support, and providing an easy link to renew for another year. Not sure how technically feasible that is but I think it'd be nice, anyway.
Cheers,
Roger