fraulich is correct, but you don't have to be making credits from product sales. Your catalog activity doesn't effect whether or not you can get cash payouts. As long as you are in the creator program and you allow IMVU to verify your account, you can accept sticker payments (or credit amounts in the amount of the sticker +10% so you can buy it yourself). IMVU will convert it to cash and you can request a payout once you hit $50+.
I know you're in the creator program, so if you want to still keep accepting credits, you can. For most users on here, the mark-up fees on IMVU are small and are hardly a burden, so it doesn't really effect sales.