Comment Re:There can be only one. (Score 1) 260
Being exclusive to schools clearly had two strong effects on its early dominance: ability to build up critical mass within a smaller user pool and increase desirability because of that exclusivity.
However, and this might not so much explain "why Facebook" as it does "why not MySpace," I think the biggest reason Facebook became dominant instead of MySpace is that its user interface wasn't a hideous nightmare and its user pages didn't all look like some wrist-slitting kid's Geocities site gotten eaten by a dog and barfed up.