Facebook started out as a social network where you could get what we today regard as PII (e.g phone numbers of the opposite gender and such) for Harvard student

Facebook started out as a social network where you could get what we today regard as PII (e.g phone numbers of the opposite gender and such) for Harvard students, and its engagement numbers were really good (based on Zuck’s previous experience with the Harvard-only FaceMash). They would later expand to other Ivy league schools — aka networks — one by one, rather than simultaneously, as a way to slow their growth. I imagine an unintended side effect of this growth strategy was the sense of FOMO that it engendered among university students that had heard about but couldn’t join the exclusive/elusive Facebook, unlike the other social networks like Friendster, Hi5 etc. For each network on their expansion list, Zuck & team would furiously scrape the student directory to seed the new network with plausible student info.