Basicly your best bet is to email them and thank them for joining tripleclicks then tell them they cannot beat the price of buying 200 tcredits on a standing order for $58 USD which equals out tobe 29 cents a peice so they can bid on the auctions. Then tell them about products that you have used from SFI and tell them how you like them. You cannot beat word of mouth on anything in this world.
