How great would it be if Stumble Upon was pre-seeded with a ton of content automatically mined from your online behavior. Manually curating a relevant stream of content requires alot of energy and effort. Right now, Facebook is the easiest, lowest effort source of content. I imagine most Hacker News readers are pretty advanced when it comes to content discovery. But the average user is not as savy. By giving them a few tools, and a clear rules about how their behavior on facebook, (liking, sharing, reading, viewing, etc) contributes to the ads they are served, it could actually become a great resource that they pay attention to