Understanding your Feedburner Numbers

I don't know if I quite understand how Feedburner works. Sure I get the theory, but like most Internet things, the numbers and stats of web applications are often a bit spooky to me, something that hovers more in the reality of paranormal than science.

But I was never good at numbers, so maybe it is just my numeraly challenged grey matter. So, back to the Feedburner issue. I was having a look at ProBlogger and found this post that actually made the whole Feedburner issue make sense for me:

Why does my Feedburner Subscriber Count Fluctuate?

Darren spoke to the font of all knowledge at Feedburner - Rick Klau (Feedburner’s Vice President of Publisher Services) and ask him for an official explanation of fluctuating Feedburner subscription numbers.