I use feedburner... You take your wordpress feed (or any feed) and plug it in to the system Then instead of offering your normal feed on your site, you offer your feedburner feed link instead.
Feedburner will tell you how many subscribers, per day/month, link clicks, off clicks, ect.. A great tool to see how many people you have reading your blog.
This plugin will focus your wp feeds all into feedburner, so you can get some real stats.
http://www.feedburner.com/fb/a/help/...ess_quickstart
This is my feedburner feed for thedocblog:
http://feeds.feedburner.com/TheDocBlog