Commuters in San Diego yesterday didn't have to pay for public transit. That's because Washington Mutual bank paid for all riders' fares:

A bank spokesman says it's one way the company is saying "thank you" to consumers who ranked WaMu tops among Western U.S. banks in a recent J.D. Power and Associates customer satisfaction survey.

A similar one-day event in Sacramento last month boosted ridership by 10 percent to 20 percent. "It was very well-received," said Alane Masui, with the Sacramento Regional Transit District.

Sure, it's just a different form of advertising. But it's a cool way for a city transit authority to take in some extra money (WaMu paid San Diego the cost of the fares plus some extra fees).

And it's effective. When I saw this story out of San Diego, I was reminded that a similar event happened in Washington, D.C., a few years ago. And I was even able to conjure up the advertiser. It was ING Direct (although I still don't really know what that company does...).