Credit card companies still make money on customers who pay in full every month. The customer who pays in full does not generate interest revenue, but does generate interchange revenue (and possibly annual fees, foreign transaction fees, and other charges). Cardholders who carry balances are still significantly more profitable per account, but the business model does not depend on you specifically being one of them.
The four main revenue streams.
1. Interchange fees. Every time you swipe, dip, tap, or enter your card number, the merchant pays a fee that flows to the network (Visa, Mastercard, American Express, Discover) and the issuing bank (Chase, Capital One, Citi, etc.). The fee is typically 1.5% to 3.5% of the transaction, depending on card category, merchant category, and transaction type. According to the Federal Reserve's data on debit card interchange, U.S. credit card interchange revenue exceeds $100 billion a year. On a $5,000 monthly spender who pays in full, the issuer's bank typically receives roughly $80 to $130 a month in interchange (after splitting with the network and processor), which more than covers the cost of running the account, the rewards program, and customer service.
2. Interest on revolving balances. The majority of revenue at most card issuers comes from cardholders who carry balances, paying APRs that average 22% to 28%. The Federal Reserve's G.19 release tracks the assessed interest rate on credit card accounts, which crossed 23% in 2024 for the first time on record. Revolvers are the high-margin segment. Per the Consumer Financial Protection Bureau's biennial credit card market report, roughly half of U.S. accounts revolve at least sometimes.
3. Fees. Annual fees on premium cards (often $95 to $695). Foreign transaction fees (typically 3% on cards that charge them). Cash advance fees (typically 3% to 5%, plus a higher APR with no grace period). Balance transfer fees (typically 3% to 5% of the transferred amount). Late payment fees, capped under the Credit CARD Act of 2009 (15 U.S.C. ยง 1666i-2) at $30 for first late payment and $41 for subsequent ones, with the CFPB issuing further fee rule changes in 2024. Over-limit fees (now requiring opt-in under the Credit CARD Act and largely abandoned). Returned payment fees.
4. Co-brand and partnership revenue. Co-branded cards (the Delta Amex, the Chase United, the Marriott Bonvoy) generate revenue from the partnership directly. Issuers pay miles or points to the airline or hotel program but also share in the program's economics. American Express's annual reports break out billed business and discount revenue (their term for interchange-equivalent), typically the largest single line.
The economics of a transactor (someone who pays in full). Industry reports estimate that transactors generate $5 to $15 of net profit per $1,000 of spending after rewards costs. A $30,000-a-year spender on a 2% rewards card might generate $400 to $500 of net profit annually for the issuer after the $600 in rewards has been paid out. That is lower margin than a revolver, but it is still profitable, particularly because transactors carry low credit risk (they pay back what they spend, so the issuer almost never has to charge off the account).
The economics of a revolver. A cardholder carrying $5,000 at 24% APR generates about $1,200 a year in interest revenue alone, plus interchange on continuing spend, minus any rewards earned and minus the credit risk of eventual default. Revolvers are the engine of credit card profitability, but a meaningful portion of them eventually charge off, which the issuer absorbs as a loss against the prior interest revenue.
What about reward cards specifically? The math on a 2% cash-back card looks tight at first (the issuer pays out $200 in rewards on $10,000 of spending), but interchange typically generates $200 to $300 on the same volume, plus annual fees on premium cards offset further. The effective net margin on a transactor with a no-annual-fee 2% card is roughly $20 to $50 a year for the issuer; not a fortune, but not nothing across millions of accounts.
Why issuers want transactors anyway. Even if revolvers are higher margin, issuers compete aggressively for transactor accounts because (a) transactors are the lowest-risk customer category, (b) life events change behavior (a transactor today may revolve briefly during a job loss or medical event), (c) interchange revenue is steady and uncorrelated with credit risk, and (d) the brand prestige of a high-spending transactor (corporate cardholders, premium cards) supports premium pricing across the rest of the lineup.
Implications for you as a consumer. If you pay in full every month, you are not getting away with anything; you are simply at the lower-margin end of a profitable business. The issuer is fine. The economics work. Use the rewards, capture the welcome bonuses, and do not feel guilty about paying off your balance, ever.
The two real risks of being a transactor. First, an unexpectedly large purchase that you cannot pay in full at the next statement. Once you carry a balance, the grace period (the time between purchase and the start of interest accrual) disappears for new purchases until the balance is back to zero. Second, the temptation to chase rewards into purchases you would not otherwise make. The 2% cash back is worth $0 if it caused a $200 purchase you did not need.
Pay in full, capture the rewards, feel zero guilt. Interchange and fees keep the issuer fine. Treat the card as a payment tool and the math runs in your favor.