The version I heard of this was “a guy got a new job at a sex store, the manager trains him and shows him around and says:’hey I have to go do somethings I will be back in about an hour’ so the guy is sitting at the counter and a white woman comes in and asks for dildos, he says we have a white one and a black one, she says I have never had a black one before I will take that one. A few mins later a black lady comes in and again asks for a dildo he explains we have a white one and a black one, she says I have never had a white one I will take that one. Well about 10 minutes later a blonde comes in again asking for a dildo, he says we have a white one and a black one, she says, I have both of those do you have anything different? He says yes!, we have a plaid one that just came in, it costs twice as much, she says yes I will take that one. The manager comes back and asks so how did you do? He says I sold a white model, a black model and your thermos.