It works exactly as FB has publicly stated. As set of topics are algorithmically detected from a variety of sources. Let&#x27;s say this set has &quot;many many&quot; things in it. Many of which are of low quality. The best comparison I can give you is Twitter trends. Humans approve some of these detected topics to appear in the trending module. Let&#x27;s just say there are now &quot;many&quot; topics. Yes, curators have the ability to insert a topic in to the trending list, and yes they have ability to make something appear in everyone&#x27;s trending module, but it&#x27;s not really used. It&#x27;s mostly there so that you don&#x27;t have to wait minutes for trending to detect that aliens have landed on the Washington Mall, or that nuclear war has broken out. In fact,  the &quot;everyone must see this now!&quot; has never been used.  This candidate set of approved topics is then algorithmically ranked for each person. Using criteria that they said.<p>If you really care, it uses a GBDT and the newly released Facebook Flow.