What is the activity feed?
The activity feed is a running stream of what's happening around the community — new public pieces and sets, fresh listings, and other shareable moments from members.
It's a great way to discover collectors and items you might otherwise miss, and to keep a finger on the pulse of the community. You'll find it in the Community area.
Only public activity shows up — anything you keep private never appears. See What's the difference between a public and private profile?.
To follow specific collectors so you catch their additions, see How do I follow other collectors?