It was a banker, and not P.T. Barnum, who first said “there’s a sucker born every minute,” writes Paul La Monica of CNNMomey.com. That axiom may prove true for major media companies in the coming months. He notes that News Corp.’s social networking site MySpace was sold for $580 million last year, sending shock waves through the traditional media industry and contributed to a big rally in the company’s stock. Now, “old” media firms are supposed to be scrambling to find their own MySpace to get reach teens and young adults.