There is a large "wealth effect" that comes with an improving housing market, which means people feel wealthier as their home value rises and therefore spend more. This is good news for American Express Company (NYSE: AXP ) and rival payment processors Visa Inc (NYSE: V ) and Mastercard Inc (NYSE: MA ). It's doubly good for American Express, which not only processes transactions but also extends credit to its customers, whereas Visa Inc (NYSE: V ) and Mastercard Inc (NYSE: MA ) work with banks who extend credit. The different business models can be seen in a recent table from Visa's annual report.