Rewards maximization has a reputation problem: it sounds like a hobby for people with laminated spreadsheets. The truth is that 90% of the value comes from one boring insight — most people put most of their spending on the wrong card — and fixing it takes an afternoon.
Find your real categories
Look at your last six months of spending by category (your finance app should do this in one view — excluding one-off purchases so the picture isn't distorted). For most households, three categories dominate: groceries, dining, and either gas or travel. Everything else is a rounding error.
Now compare what your current card earns in those categories against the best widely-available alternatives. Grocery-heavy household earning 1x on a generic card? A card earning 3–6% on groceries changes your annual math by hundreds of dollars. That gap — your actual spending times the multiplier difference — is the number that matters, not the sign-up bonus.
The two-or-three card setup
- One card with strong multipliers on your top category (groceries or dining, usually).
- One flat 2% card for everything that doesn't hit a bonus category — this alone beats a 1% card by 100% forever.
- Optionally: one travel card if you actually travel, both for the multiplier and the protections.
That's the whole system. The marginal value of the fourth and fifth card is small, and every added card is another statement date, another annual-fee decision, another thing to track.
Let software keep score
The part humans are bad at is the ongoing audit: did the setup actually pay off? The fix is measurement — a system that maps each real transaction to your card's earning rates and computes what you earned versus what the best available card would have earned on your exact spending. Run that comparison once a year. If the gap is meaningful, switch. If not, enjoy the passive income and think about it never.