18. Facebook is a utility that lets you keep track of your existing friends.
19. "If you need scale in order to create value, it's hard to get scale, because there's little incentive for the first people to use the product. [...] The system should be useful for user number one." - Joshua Schachter, inventor of Delicious, Technology Review, 2006
28. "If I went in there and said, Hey, you're using that tag wrong, people would just tell me [where to go]" - Joshua again (Or to put it another way: people are individuals.)