This D.C. diamond guru is proof that video didn’t kill all the radio starsBefore John Sabet could sell to political power brokers in D.C., he knew he had to get to know the industry’s diamond brokers, so he set off to get a diamond education that would position Charleston Alexander Diamond Importers as the area’s largest source of loose diamonds and bridal jewelry. Confident that approach would translate into sales, in 2003 he embarked on an ambitious expansion plan. Today, his operation is poised to realize $50 million in annual revenue. Something of a contrarian, Sabet places heavy emphasis on radio ads—many of which he voices himself! And he competes with the Internet’s pure players by offering superior products backed by super­lative customer service. With on-demand media, most retailers are running away from radio. Why do you stay? More than 239 million people inte