I'm a big fan of Google Reader. If a normal Internet user wanted to know whether something had updated, they'd be forced to visit that website every time they were curious. This leads to a lot of wasted time and effort, and can result in websites being totally forgotten after a period with no updates. With Google Reader, I visit one site in the morning and it gives me every update to every website I've chosen to track, all in one list. It's great.
As I check out the Reader feed, I'll find articles that interest me and, I believe, would interest others. I share them on the top-right of this very website. It seems pretty prominent to me, but I don't know if anyone uses this feature.