services billions of users (the kind of scale only rivaled by companies like Google) and worth $500b+ A lot of people, not necessarily including the author, do

services billions of users (the kind of scale only rivaled by companies like Google) and worth $500b+ A lot of people, not necessarily including the author, don't realize the niche challenges involved in running really high-scale services. They present hard problems, which just aren't there at low scale. They're Google's arch nemesis when it comes to recruiting, for one. And advertising. Facebook's advertising business is huge, probably only 2nd to Google's. Now, it is possible that Facebook's extreme focus on advertising and user engagement will drive off many of its users, in which case the advertising model won't sustain long-term. However, today it is big.