Philadelphia residents are getting 13 minutes to get a free $100.
Check out this Twitter account: @FindMePhilly. It promises "$100 if you can find me. You have 13 minutes. Timer starts when I post the first picture from a new location."
A mystery man posts a pic from a famous Philly landmark to Twitter, Instagram and Vine, and the first person to get there within 13 minutes gets a Benjamin. For free.
If no one shows up in time, the guy disappears — and usually leaves a picture of Benjamin Franklin behind.
WTXF tracked the mystery man down, but he wouldn't go on camera.
"He tells us he's not rich but did win a few thousand dollars from a recent contest. He's made a resolution to give all that money away to strangers and visit Philly sites in the process."
WTXF spoke with folks who'd gotten the $100. You can see those interviews on their website.
The mystery man says he's been getting lots of emails with people asking for money and wishes he could help them all.
This video includes images from Getty Images.