Downloading the image above to your iPhone could possibly lead to a free cup of coffee at Starbucks. No, it isn’t an ad campaign for the corporation itself, but rather a viral social experiment set up by mobile app developer Jonathan Stark. Based on the “take a penny, leave a penny” ideology, the whole system relies on user donations to the card account. If there’s no money on the card at the time it’s scanned, well, you’ll have to pony up. Since launching on July 14, the card has collected over $8,700 in donations including an initial $300 from the developer himself. If you’re not looking forward to an awkward confrontation with a Starbucks cashier, you can check the balance of the card via its own automated Twitter account. Between the two Tahzoo offices, this will definitely be “tested” several times. Guaranteed.
Update: Starbucks shut down the card account. It was fun while it lasted!