Hey! Nielsen is a relatively new offering from Nielsen - your friendly neighbourhood consumer tracking corporation. It is part stats site, part community site and all Web 2.0. It is actually pretty feature rich and takes some getting to know.
First of all, HN allows for the posting of opinions. The community aspect of this part of the platform allows for others to rate the thing about which the opinion is posted, and also to react to the opinion itself. For example, there is currently an opinion about Google entitle "Sorry, Google is evil". Here one can 'rate' Google, and 'react' to the opinion.
Drilling down on the subject of opinion, one is then presented with more data about that thing. The main focus on this page is the Nielsen Buzz Chart which includes the day to day Hey! Nielsen score and an additional chart showing buzz in the blogosphere, drawn from BlogPulse. Below is the page for FireFly:
It is perhaps a shame to see the BlogPulse data without a vertical scale, so I'm not entirely sure what it is. The explanation describes it as daily volume, but I'd be surprised if this wasn't being normalized.
The Hey! Nielsen score is less transparent:
The Hey! Nielsen score is a real-time indicator of a topic's impact and value and you play a major role. As the site evolves and users submit their opinions and commentary, the score will rise or fall based on a number of factors including, but not limited to, user opinions, news coverage, and raw data from our sister sites Billboard.com, HollywoodReporter.com, and BlogPulse.com.
However, it is interesting to see a new metric being put out there and an effort to build something around it. Nielsen would do well to provide more details about the formula being used.
Hey! Nielsen is a fun intersection of a number of social and Web 2.0 ideas. The main purpose of the site seems to be to provide opportunities for users to express opinions and to associate metrics with those opinions - data which is surely being fed back in to the Nielsen machine in many ways. One key metric that I'd be interested in finding out is the growth of users of the site. Currently, there doesn't appear to be much traction in the blogosphere, though there are a number of widgets that the site makes available. Have you seen any in the wild?