Web sites will be able to recommend their content to users based on what their friends are reading, via a new “Recommendations” plugin that Facebook is introducing today at its f8 developer conference.

Because the social data is stored on Facebook’s servers, the Recommendations plugin will display regardless of whether the user is logged in to the web site running the plugin. In terms of the recommended content,  the plugin “considers all the social interactions with URLs from your site,” according to the company, If the user is logged in to Facebook, they’ll see specific recommendations from Facebook friends.

Like the other plugins announced today, this one requires a line of code. To target the recommendations to the site, owners need to input their domain. The match is exact, so if a subdomain is entered, recommendations will be drawn from those URLs but not from URLs on the parent domain. There’s no option to aggregate recommendations across domains at this point, but that should be coming soon.

Overall, this could be a potentially very interesting way for publishers to increase engagement on their site by suggesting other content on the site to visitors based on what Facebook recommends.