You forgot about too old or tech-illiterate. I can't be the only person to have said "the iPad is the perfect device for my -insert older relative here-". And I

You forgot about too old or tech-illiterate. I can't be the only person to have said "the iPad is the perfect device for my -insert older relative here-". And I would bet there's a significant portion of that segment isn't on Facebook. Don't forget that there's a percentage of Facebook users that are businesses, fake users, "employer friendly" duplicate accounts, and people who lie about their location. That's not counting people who lie about their demographic information, either. I don't doubt there's a large number of Facebook users, but you can't take everything at face value.