First, I am not an Financial expert, so this is not expert advise!
This is how I make extra cash daily!
Rather it's a cash reward and travel reward card. As long as the Merchant does not charge a extra credit card fee. I use a credit card for everything from $0.01 to thousands. But, you have to pay it off each month. A lot of credit cards also pay you bonus cash once you spend an specific about. Example spend $500 to get $150 in cash or travel rewards depending on the card.
Many grocery stores have gas stations and offer fuel rewards. The store I shop at, you get 10 cents for every $100 up to $1.00 per fill up. max 35 gallons per Vehicle, but they only permit one Vehicle per purchase. So, i bring 3 or 4- 5 gallon gas cans to squeeze out every penny..
eBay has what is called eBay bucks, and you earn 1% on qualified items . you have to be an eBay member and signed up for eBay bucks. quite frequently eBay has promotions for 6,8, and 10 times eBay bucks. you should get emailed notified with promotions from eBay..
It will show you in the listing, if you get eBay bucks for the listing you are looking at. (see below for example)