Jonathan is letting anyone who wants to use his Starbucks card. He’s posted a scanned copy of the mobile-app code on his Starbucks card and invited anyone who wants to to have a cup on him. The crazy thing is that it’s working like “leave a penny, take a penny,” with some people adding onto the card’s balance after they grab a brew.

Starbucks reloadable cards let you download their code onto your smartphone. You can scan it from your phone at checkout in order to pay.

Jonathan released the card into the wild in July with a $30 balance on it. As of Monday, $3,651 had been spent on it, and at least 177 people had made donations to it.

Here’s a full-sized image of the card. The card also has its own automated Twitter feed that gives status updates on its balance and asks for refills.

To reload the card, go to starbucks.com/card, hit “reload a card” and enter card number 6061006913522430.

Sometimes a greedy person will transfer a chunk of the balance to their own Starbucks card but then others refill the card back up again.

Starbucks knows about the project and isn’t interfering. “We think Jonathan’s project is really interesting and are flattered he chose Starbucks for his social experiment,” Gina Woods, director of executive communications for Starbucks, told CNN via e-mail. “We’re curious to see how his project continues to evolve.”

One blogger posted what he says is evidence that Jonathan is secretly working for Starbucks. Jonathan strongly disputes these accusations.

Want a cup of coffee? Use Jonathan’s card [CNN] (Thanks to David!)

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