A billion people are on Facebook. That puts it right up there with television, chocolate and Mandarin Chinese.
Facebook announced its billionth user today. That's a lot of people! It's nearly half the people with internet access, and 15% of all the people that are alive at all. More people use Facebook than own dogs, or watch the Super Bowl.
To help you further comprehend the sheer scale of giga-Facebook, here's a few other things with a billion users.
1.4 billion households have TV, per the most recent count.