Before that, my friends were on LiveJournal and after Friendster was a little site called MySpace. I've been trying to separate startups into ones you could do

Before that, my friends were on LiveJournal and after Friendster was a little site called MySpace. I've been trying to separate startups into ones you could do customer discovery for before you build the app and ones where you have to see it to get it. I think Facebook falls in the first category and Twitter falls in the second category but I'm not exactly sure why.