How many readers do you really have?

I came across the answer by discovering Feedburner. I burnt a feed for my blog, and then I completely forgot about that (it was an early stage of my blogging, so I had a very loose idea of feeds and their use). Last week, I rediscovered Feedburner, but this time I found out how to publish the number of readers you have on your blog. I was disappointed that there were only 4 readers.