Facebook was designed to "make the world more open and connected", but recently people have been using the site in another way – to buy and sell items.
More than 450 million people are visiting "buy and sell" groups each month, and the firm is rolling out a feature that helps them make more of these connections.
Called Marketplace', this trading platform lets Facebook's 1.71 billion users list or search for items on sale in their neighborhood – putting them in competition with eBay and Craigslist.
"Marketplace makes it easy to find new things you'll love, and find a new home for the things you're ready part with," Mary Ku, director of product manager at Facebook, shared in a recent blog post.
"We'll continue to build new options and features to make this the best experience for people.
"The new feature helps facilitate this with 'a convenient destination to discover, buy and sell items with people in your community."
The trading platform will display photos of items for sale based on proximity, and users can adjust their location and search for specific items or categories such as clothing, household items or electronics.
Buyers and sellers can message each other, make or accept bids and make arrangements for delivery of the goods being sold.
Although Facebook is not charging users, the new selling platform could one day offer the potential to further monetize its global user base, and keep them on the network.
To find a specific item, simply search at the top and filter your results by location, category and price.
There are also categories such as Household, Electronics and Apparel –in case you just want to see what is being sold in your neighborhood.
Once you see something that piques your interest, tap on the image and the details from the seller will be presented.
This includes a product description, the name and profile photo of the seller and their general location - which could be much safer than meeting a seller through Craigslist.
Another difference from Craigslist is that users will be able to save an item using Facebook's Marketplace and revisit the potential purchase at any time.
If you decide to move forward with the purchase, you can contact the buyer and chat using the app.
From that point on, you and the seller can work out the details in any way you choose.
And what is different from eBay is that Facebook does not facilitate the payment or delivery of items in Marketplace.
If you're looking to sell an item, simply take a photo of it, enter the information such as description and price.
Then just confirm your location, so the item for sale will appear to buyers in your area, select a category, and post it.
The new Marketplace will be rolling out to users over 18 years old in the United States, Britain, Australia and New Zealand in the coming days on the Facebook app for iPhone and Android, with additional countries and a desktop version planned in the coming months.
The launch is Facebook's second time around for an online marketplace after a 2007 effort that failed to gain traction.
In recent years, Facebook has been testing a 'buy button' which allows its users to instantly purchase items for sale from its online partners.
In September it unveiled a new online payment system that will allow businesses to sell directly to consumers on its Messenger application.
Facebook has also been an intermediary for 'virtual goods' for online games played on the social network.