Odysseus Papadimitriou, on October 25, 2016 in Washington, D.C.
Odysseus Papadimitriou, on October 25, 2016 in Washington, D.C. Eli Meir Kaplan

A Calling to Create Smarter Tools

Backstory: Emigrated from Greece for college in 1996.

Education: Degrees in economics and civil engineering from Brown University, MBA from Duke University.

Profession: CEO and founder of WalletHub.

Vision: Create the smartest free web-based financial adviser.

When Odysseas Papadimitriou left home for college in the U.S., he had every intention of returning. Greece was gearing up for the 2004 Olympics, and the economy was booming. But then he saw the chance to gain more experience by way of a job in banking. Eight years and an MBA later, he saw another opportunity—"build the brain of a financial adviser" online. First up: a credit card comparison site. "What existed seemed out of date," he recalls. Today WalletHub has more than 80 employees and 18 million visitors a year to its financial services review site.

His Credit Lessons

Don't be in the 1%. Never settle for a card that gives you less than 1.5% cash back (unless you carry a balance). "People have cards from 10 years ago getting 1% because they don't know they could get 2%," Papadimitriou says.

Clean out your wallet. Once a year, revisit your card choices: what you are earning, what you are paying, and how your spending has changed (more overseas travel, say). "Companies rely on your brand loyalty and raise fees accordingly," he says. "They know most people are too lazy to switch."

Give your teen credit. Get a secured credit card and have your kid put allowance money toward the $200 to $500 cash collateral. "If they put money on their own card," he says, "they will build good habits."

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