these can be tricky, but they can also be profitable. Most checking accounts have programs where you can earn cash back. I, for one, am a cash only kind of person but we have a debit for online purchases.
But if you are one who uses a debit card often this may be profitable. Depending on your bank there is a fee associated with such cards. For example, I was using Chase. The annual fee per card ( we had 2) that it came to $50 a year I think. I earned $70 in rewards. So I made a $20 profit.
These programs can be worth it and if you go over the fine print, you should turn a profit.