People come back because craigslist has monopoly power. Craigslist knows this. They are afraid to release an API that would allow people to experiment with UI b

People come back because craigslist has monopoly power. Craigslist knows this. They are afraid to release an API that would allow people to experiment with UI because they know that would train people to go to sites other than craigslist (I save hours using padmapper over Craigslist).