Facebook will start rolling out Marketplace this week. It's essentially Facebook's way of taking on Craigslist and eBay.
It lists items that are listed for sale near you, which you can sort by category. If you want to buy something, you message the buyer directly and work that out -- there's no payment system built into the Marketplace portal, which runs in the normal Facebook app.
Anyone 18 years or older can use Marketplace, according to Facebook's announcement.
You might run into Marketplace by accident at first. It'll replace your Messenger button within the Facebook app soon.
Why this makes sense for Facebook
Industry experts said Facebook is in prime position to launch this kind of informal marketplace.
'"Facebook already has a ton of what you might call the scaffolding you'd want to build around a commerce strategy in place," Jan Dawson, chief analyst with Jackdaw Research, told USA Today.
In other words, Facebook already knows where you live and what brands you like, and it has Messenger for customer service.
So what can't I buy?
You can't buy or sell anything illegal (including marijuana) or guns.
Am I having deja vu?
No. Facebook did try to launch an almost identical marketplace in 2007, also called Marketplace, USA Today reports. It didn't exactly take off. The 2014 effort, called For Sale Groups, is still ongoing.
Here's Facebook's Marketplace announcement of... itself.