Stoozing is where you use a card offering 0% interest on purchases for all of your shopping - and put the money that you would have otherwise spent in a high interest bank account.
Then when the introductory 0% rate is coming to an end, you simply wthdraw the cash from the bank and pay off your credit card in full.
This way, stoozers make money by paying no interest on their purchases while earning interest on the money they would otherwise been spending.
This is not the same as rate tarting, where you transfer existing debts to cards with a 0% interest rate, thereby saving on interest payments.