I absolutely believe these numbers. I know people that are completely hooked on facebook. To them, it's almost like their entire purpose on earth hinges on the activity of their facebook account.
I don't have an account myself, but I should probably check it out.
I've been completely turned off by my 40-something divorced sister-in-law that acts like she's in high school, and spends most of her day checking her facebook account. It's like everyone wants a second chance at being in the popular crowd in high school.