Who Actually Pays for Your Rewards

You earn 2% cash back on a $100 purchase. The card company hands you $2. Where did that money come from? The answer involves interchange fees, cross-subsidization, and a system where people who carry balances effectively pay for the rewards of people who don't.

The three revenue streams

1. Interchange fees (the biggest one)

Every time you swipe your card, the merchant pays a fee to accept the payment — typically 1.5-3.5% of the transaction amount. This fee is split between your card's network (Visa, Mastercard, Amex), the issuing bank (Chase, Citi, etc.), and the payment processor. The issuing bank's share — called interchange — is the primary funding source for your rewards.

On a $100 purchase with a 2% interchange rate, the merchant receives roughly $98 and the card issuer keeps roughly $2. If your card earns 1.5% cash back, the issuer is spending $1.50 of that $2 on your rewards and keeping $0.50 as profit. The economics work as long as the interchange rate exceeds the rewards rate — which is why no mainstream card offers more than 6% in any category for long.

2. Interest from cardholders who carry balances

When someone carries a balance and pays 24% APR, the issuer earns significantly more than they pay in rewards. A cardholder who spends $2,000/month, earns 2% back ($480/year), but also carries a $3,000 revolving balance at 24% APR generates roughly $720/year in interest for the issuer — far exceeding the $480 in rewards. The issuer profits $240/year from this cardholder, net of rewards.

Meanwhile, a cardholder who spends $2,000/month, earns 2% back ($480/year), and pays in full every month generates the issuer roughly $480/year in interchange but costs $480/year in rewards. The issuer breaks even or takes a small loss on this customer. The interest-paying cardholders are subsidizing the rewards of the pay-in-full cardholders.

This cross-subsidization is the economic engine of the rewards industry. Card issuers don't mind paying generous rewards to people who pay in full, because those cardholders attract others who will eventually carry a balance. The rewards are marketing spend.

3. Annual fees

Annual fees are direct profit. A card with a $95 annual fee that earns the cardholder $500 in rewards costs the issuer $500 in rewards but recoups $95 from the fee plus ~$360 in interchange on the underlying spending. The fee makes premium cards viable even for customers who never pay interest.

What this means for you

If you pay in full every month, you are playing the system correctly. You earn rewards funded primarily by interchange fees (which the merchant pays, not you) and by interest from other cardholders (who are paying for your rewards without knowing it). The card issuer may break even or take a loss on you individually, but they consider you a customer worth having because you drive transaction volume.

If you carry a balance, you are funding other people's rewards. The interest you pay exceeds the rewards you earn by a wide margin. A cardholder earning 2% back but paying 24% APR on a revolving balance is losing 22% net. No rewards rate can offset that. If you carry a balance, the most important financial decision isn't which rewards card to get — it's to pay off the balance.

Merchants pay for rewards indirectly, and so do you. Interchange fees are baked into the prices of everything you buy. Merchants raise prices to cover the 2-3% they pay on every card transaction. This means cash buyers are effectively subsidizing card rewards — they pay the inflated price but earn nothing back. Some economists argue that credit card rewards are a regressive transfer from cash users (who tend to have lower incomes) to card users (who tend to have higher incomes). That's a policy debate beyond the scope of a card comparison site, but it's worth knowing where the money comes from.