When I was a kid, people were doing the exact same thing, only with the U.S. mail, dollar bills, and much bigger pyramids. I'm kind of surprised it took this long for me to hear of a social-media/online-payment accelerated version.
There was a popular one few years back called "money flipping". Mostly on Instagram and Facebook. Not sure if it was a pyramid format but definitely a get-rich-quick scam.