The Wal Mart ad telling black guys they are kings limits them to be one kind of black guy, when really there are all kinds of black guys. Some are kings, some are jesters, some are soldiers, some are workers, some are troubadours, some are artists or poets, some are athletes, some are farmers, and the list goes on, just like any other group of people.
The one who made the Wal Mart ad telling back guys they are kings most likely wasn't black (or male). The one who benefits the most from it most likely isn't black (or male).