Or another pattern, which I presume CC companies bank on : People forget to pay in the grace window and hence get charged _some_ interest, and often get into a pattern where they pay off the wrong debts first etc.
So they're earning upto 4.5% on their savings, and then paying out like 20-25% on the debt.
So they're earning upto 4.5% on their savings, and then paying out like 20-25% on the debt.