LeeAnn Prescott at Hitwise takes a look at the Web-based RSS market and finds that Google Reader is gaining market share but lagging far behind the leader, Bloglines.
According to Hitwise, Google Reader has only one-thirteenth the market share of Bloglines, and it is well below Rojo and slightly below Newsgator as well. Google doesn't release its usage stats through Feedburner, so it's difficult to get a complete picture of how well or poorly the app is doing.
I think with Google Reader, as with Google Finance, Google concentrated too much on cutting-edge technology and not on usability, which is ironic given that it surely meant for the nifty AJAX to make everything easier on the user. I switched to Google Reader a few weeks ago, and I can safely say there's no incentive for anyone to make the switch. Bloglines is faster.