I don't think supporters get anything although I could be wrong (it'll happen one day ). It does include (iirc) a reminder to go gift the supporter if not already done, so perhaps thats where the boosters come from.

I'd like them if there was some 'loyalty' bonus that racks up points which then can be redeemed for a booster gift and if you could turn off the pop-ups for either a mail or better still a daily list of messages in a Supporters icon.