UGC would be tough, because I'm at a chicken and egg state right now as you pointed out. And crap comments would lead to more crap comments. Imagine if Quora or Hacker News had a comment bot. Sets a bad tone for the future.
i guess there may be a flaw in my initial strategy.
when training my algorithm (and as i make iterations), I compare the results to google news to make sure we're as good if not better. That's why a lot of the initial top-level categories match up pretty closely.
Sports vs sports http://sports.rawsignal.com/ http://news.google.com/news/section?pz=1&cf=all&ned=...
However, once I'm more confident in the algo, I'll let it loose on something more niche, like college football
http://collegefb.rawsignal.com/
that's how we can differentiate from google, but i never realized that having too many options would paralyze people.
maybe if i release each vertical under its own domain . . .