I looked at my last four posts. (That's fewer than I post in an ordinary month, but with a new role, I've been less productive than usual.) For each post, I looked at the number of comments left on the blog, the number of comments left on Buzz, the number of "likes" on Buzz, the number of times a link to the post was posted to Twitter (numbers courtesy of Backtype), and the number of comments on Facebook (I import every post as a "note" in Facebook).
Here's the data:
As you can see, the vast majority of engagement - 56%+ - occurs on Buzz. Next is posts on Twitter (though, it should be noted, that those are pointers to the blog post), followed by comments on my blog, followed by Facebook. (For reference purposes, the second sheet of that spreadsheet contains the numbers of each service's audience for my content, which is imperfect but directionally helpful in interpreting the results.)
Several things skew the results, to a degree: 3 of the 4 posts were about Google, so it becomes clear that my friends on Facebook could care less about my thoughts on Google (and, one could argue, that people on Buzz are disproportionately interested in Google-related stuff). Time is also a factor - comments on blog posts are more numerous the older a post is, though it's also apparent that when a post "pops" on Buzz it can drive a tremendous amount of activity nearly instantaneously.
This is an incomplete analysis, of course. I don't have any insight into how many people actually read my posts on Buzz, so I can't measure engagement as a percentage of activity. (I have this data for FeedBurner and Google Analytics, so I may re-run this analysis and incorporate that consumption data to get more insight... alas, I'm just about done with this morning's cup of coffee and I have a full day ahead of me.)
Disclaimer: I'm a product manager at Google, I work closely with the Buzz team as the PM on Profiles. This is my own data, published purely out of curiosity.
