Rich Skrenta writes about the architecture and ambition of Craigslist:
Craigslist is brilliant because his main activity is something that posters are inherently promiscuous with — personal spamming. In any other context, the bulk of the material on Craigslist would be considered spam. In my email box, on another message forum, heck even on one of google’s spam-ridden Blogger sites. The posts are the equivalent of those indiscriminately posted flyers on corkboards at universities.
Buy my mattress..need a ride to Chicago…come see my band. People put these flyers up fully expecting only a handful to see or care about them enough to rip off a tab with the phone number at the bottom. The expectation of response is low but it’s cheap to try.
Now Craig’s lead-into-gold trick is that he gets his posters to accurately classify their spam. Into 160 categories. Holy Toledo Jacob Nielsen. You can’t have a pulldown with 160 things in it. Half of your users wouldn’t get a pulldown with 3 things in it right. Ah, but it’s not a pull-down. Half of the entire homepage is a giant selector devoted to classifying posts.