Sigh... I use Mariott in Cambridge MA once a month so was hoping I'd be invited to join Gold but as I'm already a silver Mariott holder I get nothing. I emailed them and they said they were sorry but that's the way BA chose to run things.
Shame, I would have got more points = more miles if I'd wangled it.
Seems a little ...-backward to me.
DocW
p.s. Mariott did say (in consolation?!) that the Gold status isn't permanent; if you don't stay 50 nights you lose it.