> Or is this only financially viable due to the transaction fees the credit card companies get? Yes. These reward cards work out to about 1-2% cashback equival

> Or is this only financially viable due to the transaction fees the credit card companies get? Yes. These reward cards work out to about 1-2% cashback equivalents after the sign up bonuses. From the credit card perspective, the financials are basically identical to their normal "cashback cards". If you are like me and just want a couple free plane tickets a year, you just pick up 4 new credit cards [~160-200,000 points/miles] and cancel them. If you put 100% of your spending on credit cards and just cycle through the sign up bonuses every 3 months, its really easy and 160k miles is 2 round trip tickets a year anywhere domestically, with some leftover.