I "installed" FeedBurner on this blog about 20 days ago and for the first ten days the stats reporting was really flaky. The last week or so it has been very stable and today we just reached, for the first time, 300 feed subscribers.
Add to that the 96 "email subscribers" and we have a stable audience of about 400 readers.
Now, me being the person that I'm (i.e., love stats and their tools) I can attest this is absolutely not the reality. First of, feed subscriber count has many flaws (search for Vanessa Fox post about it), like "dead subscribers", or people that just glance at the title of your post. Second, email subscribers also doesn't guarantee that anyone actually opened the email and read it.
Do I think 400 people read this blog everyday? Absolutely not, but close.
Google Analytics (which doesn't include Feed readers) averages about 200 visitors per day, if you assume 50% of the feed subscribers do read the content, that adds another 150 not counted by Google Analytics, for a total of 350 readers per day. Not that far from Feedburner stats.