I think this is spot on.. but you've actually understated FB's market penetration, because only 1/2 of the world population is on the internet.. as of 2016: 3.4

I think this is spot on.. but you've actually understated FB's market penetration, because only 1/2 of the world population is on the internet.. as of 2016: 3.4B. 750m of those are in China.. so 2.7B. (of course it'll be a bit higher than this, because it has certainly grown somewhat since 2016.) And from that, now you can exclude children, reliable access, and people who dont want to use it, etc. https://en.wikipedia.org/wiki/List_of_countries_by_number_of_Internet_users https://en.wikipedia.org/wiki/List_of_countries_by_number_of...