Saatchi

I find Charles Saatchi to be such an interesting figure in the art world. His position as a "famous" collector is a challenging concept. How does one become famous for buying other people's art?
He is an advertising executive yet he his also known for his impact on the art world. But can a collector really have an impact? Is that fair to the artists? Saatchi has become more famous than some of the art work that he owns. This idea of the all star collector appears to be a construction of the modern art world and the transformation of art as a commodity. Yet it is men like Saatchi who were the early supporters of contemporary art. Arguably without them artist like Damien Hirst would not have been able to continue to make art.
Yet how does this effect the art world, and the work that is being produced. The big question becomes...Is Saatchi a positive figure who gave/gives recognition and support to emerging contemporary artists? Or is he part of the problem, because he cornered the market of the YBAs and was a major player in communication of modern art? Or is he both?