All that glitters is gold
I've always argued that comments on blog posts, news articles and discussion threads are a goldmine of information and in many cases provide much richer insights than the original post. Years ago when Scott Ritter (a US Marines intelligence analyst) was responsible for finding WMD in Iraq after the invasion he wrote an article about how as much as 70% of the content of secret US national intelligence estimates (NIE) are composed of information that's in the public domain. CIA analysts conduct good old fashioned 'police work' by trawling newspapers, internet chat rooms, gossip columns, online communities from around the world by labouriously connecting the dots. Only a small proportion of the content of NIEs contain information from spycraft sources and activities; satellites, intercepts, surveillance and so on.
Commenting is a science in its own right
The New York Times has been covering a number of new developments in commenting technology using YouTube as an example.
As anyone who has slogged through YouTube or an article about anything even remotely contentious online knows, commenters are often like the drunken uncle no one wants to invite to the house for Christmas, but he shows up anyway.
YouTube is addressing this very issue, see: YouTube Comments Will Soon Be Less Racist, Homophobic, and Confusing
Slashdot made a major breakthrough by finding a way for users to mderate each other when there can be hundreds or thousands of comments on a single post. A new service called Kinja is revolutionising content by making comments more prominent than posts. Collective intelligence is all the rage as long as it can separate the signal from the noise.
Anger is more influential than joy
Clay Shirky, a leading social software scientist says people forward posts they like and comment on the ones they hate. This seems to be true based on a recent study (PDF) by Chinese academics of Weibo, China's equivalent of Twitter. Their research says that anger spreads faster than joy. That's a shame but not surprising as we all know bad news sells more than good news. Weibo has 500m users and generates 100m Tweets per day.