Secret Sister is a chain letter-type gift exchange pyramid scheme that has been primarily spread through Facebook.
[2][3][4] In a typical post, participants are given a list of six names and are asked to send one gift (or book, or bottle of wine) valued at about $10–15 USD to the person at the top of the list.
[1][5][6] Unlike a typical Secret Santa exchange, where participants only give and receive one gift, Secret Sister participants are unlikely to receive the promised gifts.
This is because an exponentially growing pyramid of gift givers and recipients cannot be sustained indefinitely.
[7] According to Snopes.com, while a handful of people claim to have received a single gift when participating in a Secret Sister exchange, there is no evidence that anyone has received a substantial number of gifts via this scheme.