So you think that your feedburner count is low and your actual visitors might be many more?
First step is to set the Feedburner default single feed and tweak the autodiscovery settings such that only one feed is accessible to your readers. This ensures that the total feedcount includes all your readers.
If you had not set this before, WordPress Feedburner plugin redirects all your readers from your original wordpress feed through Feedburner. So your feedburner chicklet / counter will show a sudden increase in number of subscribers. The feedburner counter is the one you see on the right which shows the number of feedburner rss feed subscribers.
It is available in 2 versions for WordPress 1.5 and WordPress 2. Install the correct version. Remember that the comment feeds are still served from WordPress.
I am new to WordPress so I have my feed set to default feedburner. But if were offering both your original as well as feedburner feed to your readers, your counter should see a jump in number. Try it and tell me…