The document discusses Chris Anderson's concept of the "Long Tail", where businesses can find commercial success by catering to niche interests in the "tail" of the demand curve in addition to popular interests in the "main body". It provides examples of businesses like Facebook and play.com in the main body and more niche sites in the tail. It also discusses case studies of how businesses like Facebook, play.com and Ultimate-guitar.com leverage the Long Tail. Criticism of the Long Tail theory is mentioned as well as how crowds can perform collaborative work in the tail.