by 
Price again, this time with details of a study (pdf) conducted by Buzzmetrics which offers some interesting data on blog comments. As suspected, you can’t accurately monitor blogs, without monitoring comments.
As the report concludes…
…according to our analysis, comments constitute a substantial part of the blogosphere, accounting for up to 30% of the volume of weblog posts themselves…we show that usage of comments improves weblog retrieval (in terms of number of results), and is beneficial for ranking weblog posts in new, potentially useful ways.
We discuss comments as an indicator of the popularity of weblog posts and weblogs themselves, and find —as expected— that a wealth of comments in a weblog is a good indication for the significance of the weblog.
Finally, we offer a novel way to determine the level of controversy caused by a weblog post by analyzing the type of comments written in response.
