NASHVILLE, Tenn. (WKRN) – Spend $10 and get dozens of presents in return. That’s the promise of the Secret Sister Gift Exchange, and it’s making the rounds again on social media just in time for Christmas.

The Better Business Bureau warns this gift exchange is not only a scam, it’s illegal.

Search “Secret Sister Gift Exchange” on Facebook and wait for the posts to load. Scroll through and see just how many people are sharing the holiday proposal.

One user posted, “Who doesn’t love to come home to packages, especially during the Christmas season?” Another person promised as many as 36 gifts after buying just 1. And another person posted, “This is not a scam, pyramid or anything else – it’s just FUN!”

The BBB disagrees, and it is letting people know to avoid this gift exchange and others like it.

The BBB says the deal is a digital chain letter, making it an illegal scam.

According to the US Postal Inspector, chain letters are a form of gambling that are, “illegal if they request money or other items of value and promise a substantial return to the participants.”

The Secret Sister Gift Exchange requires people to spend $10 on a gift and promises up to 36 in return. The more people you get to sign up, the more gifts you receive. Once you agree, you’re told you’ll get the information on where to send the gift.

The BBB says there are some problems with this offer, besides the possible mail fraud charge.

The scam requires you to share your personal information, like your name and home address. You don’t know who all will get that information or what their intentions are.

The BBB says another problem is there’s no guarantee you’re going to get the gifts you’re promised.

Although tempting, the BBB says if you see this gift exchange on social media – ignore it!