For the last couple of years you've been able to send and receive money on Facebook Messenger, but you've only been able to make those transactions between you and another person.
Starting Tuesday on Android devices and on desktop computers, you can send or receive money between groups of people on Messenger for free.
Facebook's blog post describes scenarios where you're splitting a restaurant bill or chipping in for a group gift. To make a group payment, you go to a new or existing Messenger group conversation, tap on the plus sign in the bottom left corner to find more features, and tap the payments icon ($). You then choose who to send or request money from. You can select a single member of the group or everyone in the group.
It's unclear why Facebook has started with just Android and desktop and hasn't launched the feature yet for Apple iOS devices. Whatever the case, the new feature indicates that Facebook is ostensibly competing with Venmo, which started out as a payment system but has morphed into a quasi social network.