Facebook is an important source of traffic for many companies, including online publishers.

And a new search engine Facebook is testing in its iOS mobile app could enable the world’s largest social network to generate even more referrals for third parties.

As reported by TechCrunch, some users are seeing a new “Add a Link” button when they post status updates. When clicked, this button allows users to enter a search query and displays relevant links that Facebook thinks the user might want to share.

While it’s not obvious how exactly Facebook is determining which links it returns in search results, TechCrunch’s Josh Constine observes that “results seem to be sorted by what users are most likely to share, highlighting recently published sites that have been posted by lots of people.”

According to Facebook, it has indexed more than a trillion posts so it certainly has a lot of data to work with. Overlaid with data from its vast social graph, Facebook has the potential to do interesting things that Google can’t with its search results.

A boon for publishers, brands?

If rolled out broadly, Facebook’s new search functionality could be a boon for publishers and brands, particularly those active on the content marketing front. But they shouldn’t expect a free lunch either.

As it applies EdgeRank to determine what appears in user feeds, it seems probable that Facebook would employ a similar algorithm to search results. 

Search functionality also lends itself to monetization. It’s not hard to imagine an ad product that helps publishers and marketers promote their content through sponsored search results, giving publishers and brands willing to spend a leg up on frugal competitors.

Finally, Facebook could theoretically use this search feature to incentivize publishers to participate in its Instant Articles initiative, which asks publishers to host their content on Facebook.

If the social media giant prioritizes Instant Articles content in search results, it could be a powerful carrot as Facebook seeks to lure publishers but could also leave non-participants at a disadvantage.

Clearly, Facebook has the ability to develop new ways to help them better reach the billion-plus people in its network and, most importantly, is working to do so. Even if there are strings attached, if Facebook can deliver more social referral traffic overall, it will be good news for publishers and brands.