They send out invites weekly to biweekly intervals, everyone is accepted. I don't see why these are $25, if they are I've got 4 accounts with it.. so just consider this a free bump if so.
O dont mine, same is for PoE, and few others MMO's. Some ppl dont have luck and want to buy it....thats easy for me I myself bought Diablo 3, why you ask, while they're sending invites each day...hehe