Robert L. and Sheila Johnson: Black Entertainment Television (BET). Robert and Sheila Johnson co-founded Black Entertainment Television (BET) in 1979, the first cable network targeting an African American market. BET officially launched in 1980, initially broadcasting for two hours a week. Nearly a decade later in 1989, Sheila abandoned her music business to join BET full time as head of community relations; she also developed and produced the talk show, Teen Summit. Â BET continued to grow, reaching tens of millions of homes and expanding to include other traditional and digital channels. It was among the first black-controlled companies to be listed on the New York Stock Exchange in 1991. Two years before their divorce, Viacom announced plans to purchase BET in 2000, finalizing the sale a year later for reportedly $3 billion. Bob remained as BET’s chairman and CEO until 2006 before leaving launch the RLJ Companies. Today, both Johnsons are billionaires, ranking among the wealthiest African-Americans in America.