It isn't important, that you have an Exduct account with your BLF username - you can have every username you want. Some of us, use their BLF usernames, others not.
Then use the BLFcode "BLFgiveaway" (without ""). If we have bought enough (and the forum get the 5x $20 coupons) Vectrex open a new thread (he did it in the past and maybe in the future, too) like this one:
You have to write in the thread raffle thread, which order number is yours and maybe you will win one of the $20 coupons.