Feedburner, that hosts more than 600,000, is in a good position to offer some statistics about feed readers. The most popular feed readers are web-based, so it's interesting to know how they stand. Feedburner decided to ignore the total number of subscribers, because it's pretty irrelevant, and looked at the number of posts that are actually read and at the number of clicks to the original site.If you look at the number of clicks, the top 5 web feed readers are (it's interesting to note that Yahoo is the only one that displays only the titles):
1. My Yahoo 54%
2. Google 21% (Reader + Personalized Homepage)
3. Bloglines 11%
4. Netvibes 9%
5. Live.com 3%
In terms of post views, the situation changes a little bit (Yahoo couldn't be included here because you can't read posts inside My Yahoo):
1. Google 59%
2. Bloglines 33%
3. the others had 3% or less.
So the most important online feed readers are My Yahoo, Google Reader/IG and Bloglines, although it's hard to make a comparison between Google and Yahoo from this data. Google has more subscribed than any other feed reader, though: 76% from all FeedBurner feeds have at least one Google subscribers, unlike Bloglines (63%) and Yahoo (51%), which don't have a wide coverage.
Google and Bloglines seem to attract more tech-oriented users, but also more diverse users than Yahoo (hence the feed coverage). Google tries to satisfy both users who read a lot of feeds (and would choose between Google Reader and Bloglines), and users who subscribe to a manageable amount of feeds (Google Personalized Homepage or My Yahoo should be a perfect match), so it's in the perfect position to become the number one destination for reading feeds, if it's not already there.