Why do online newspaper job classifieds bring you to an external site like yahoo or career builder?

why don't the newspapers put the job classifieds straight from the paper onto their website? ie: The Los Angeles Times jobs classifieds (online) directs you to career builder. I dont live in the area so I cannot simply buy the newspaper thats why im trying to browse the newspaper classifieds through the internet.|||I am in NY and career builder is associated with Newsday and Monster.com is associated with the NY times the papers must get money for it best answer I can think of sorry.