<prompt> Human: For example, if you have 3 credit cards, and you use one to pay rent which is 1000 per month. You pay it with a card that gives 1 cash back, netting you 10. Then you pay off that credit card with another card getting you another 1, and then with a travel rewards card giving you 1000 points.This cant be possible, right? I swear I have heard of people paying off credit cards with other cards.  <response>: you dont earn rewards on balance transfers and you get charged a fee for transferring a balance. so your 1000 balance becomes 1050 when you transfer it the first time, 1102.5 the second time you transfer it, and youve earned zero rewards in the process.there are weird loopholes from time to time, like some the healthy choice thing or the US mint thing but they always close those loopholes before you find out about them. 