That's the thing I've never understood. On the one hand, on the nightly news Facebook is discussed as if everyone has an account (and that privacy changes actually matter to most viewers). On the other hand, none of my close friends use facebook.
I'd say you're lucky. Most of my friends use Facebook. I refuse, so I'm out of touch with most of them. I figure if we aren't willing to keep in touch in other ways, our friendship isn't holding up very well anyway.
The population of the earth exceeds 7B (http://www.census.gov/population/popclockworld.html) so in fact the average person on Earth does not use facebook
*unless you live in a vacuum where 1/7 counts as half
"Stop living in a vacuum ... the average person on Earth does, in fact, use Facebook."
No qualifications made for internet access
You can't just take your single data point (my close friends aren't on Facebook) and then extrapolate it (most people aren't on Facebook).