Following Topics?

I didn't see anything that was related to this and might cause too much load (thus it hasn't been implemented), but is it possible to follow specific topics and just get dung if it's "unread"? I mean it's fine, I know bookmarks exist for a reason and such, but it'd be cool to see a notification for a page I follow being unread. However, I understand that having a heartbeat for this kinda thing may be overwhelming on the DB, so you may ignore me. I think you can follow people though? Meh.