I opened my cash back app to see I had “earned” $47 last month. Then I looked at my credit card statement. I had spent three hundred dollars more than usual. The math was not mathing.

Cash back apps are brilliant at one thing: making you feel like you are saving money while you spend it. The psychology is real. Ten percent cash back feels like a discount, so you buy things you would not have bought otherwise. The app wins. The retailer wins. You lose money and feel good about it.

I almost deleted all of them. Instead I made one rule that fixed the problem.

The Rule: Only Use Cash Back on Things You Were Buying Anyway

Gas. Groceries. Toilet paper. The Amazon subscribe-and-save order you have had for two years. These are non-negotiable purchases. Cash back on necessities is free money. You were buying them regardless. The two or five percent you get back is pure savings.

The danger zone is “discover” and “deals” tabs. A coffee maker you did not know you wanted until it was forty percent off with eight percent cash back. You were not in the market for a coffee maker yesterday. Now you are spending sixty dollars to “save” five. That math is broken.

Stack But Do Not Chase

Stacking — using a cash back credit card through a cash back portal on an item that is already on sale — is smart if the item was on your list. Chasing — browsing the app to find things to buy — is how you lose money. Delete the apps from your home screen if you find yourself opening them when you are bored. Keep them, but put them in a folder labeled “Tools” not “Shopping.”

The Apps Worth Keeping

Rakuten (formerly Ebates) is the easiest — browser extension, auto-applies cash back at checkout. Ibotta requires scanning receipts but works at grocery stores and Walmart. Your credit card probably already offers cash back portals — Chase, Amex, and Citi all have them, and the rates are often the same or better than third party apps.

Use one portal. Do not try to optimize across five apps. The mental overhead is not worth the extra one percent. Pick the one tied to your credit card ecosystem and stick with it.

My new monthly average is about fifteen dollars in cash back on things I needed anyway. Last year I was “earning” forty seven dollars while spending hundreds more. The difference is the rule.