What are the trends in feed reader usage? As the overall trend in consuming online content via feeds seems undeniable, the issue of who is cornering the market becomes pretty important. LeeAnn Prescott recently wrote on this from a traffic point of view, reporting that Bloglines is still dominant with Rojo making a clear increase. Personally, my preference is to (somehow) look at traffic to blogs and feedburner type statistics to determine really how popular such services are. An earlier look at this indicated that Bloglines was dominant, though possibly declining.
Below, I've created a some graphs that may or may not be of interest. The first compares mentions of Bloglines with Google Reader. So, one might infer from this that in terms of discussion, there isn't much of a difference.
Next, we look at discussion and linking to Bloglines. The significant increase in links to Bloglines is, I believe, accounted for via the inclusion of buttons in posts that allow readers of the blog to simply subscribe to a feed via Bloglines. Incidentally, this brings up a vital issue in search - document analysis. These buttons are not part of the content of the blog post and yet they get indexed as if they were.
Thirdly, here is the same graph for Google Reader.
In summary, it is interesting to note the difference between discussion around the services and the apparent difference in usage as reported by LeeAnn. Secondly, I feel more and more that blog search engines are doing a very poor job of indexing the object content of posts, mixing in things like tags and buttons: Technorati, BlogPulse and Google BlogSearch are all guilty here (Sphere doesn't index links - or at least doesn't appear to permit search over them).
Note that I would have liked to have included trends from Google Trends - which shows changes over time in the volume of searches for a term - however that system doesn't provide any quantitive information, just the shape of the trend, so not really of any use.