Mikolette / Getty Images The razor-razor blade model involves selling a product at a low price and maybe even at a loss with the goal of selling a related product later for a profit. The model ...

Twelve-year-old Otieno is an orphan. He lives in Kibera, one of Africa's largest slums, where he has to steal to survive. Otieno is a member of the "razor blade" club that is something of a substitute ...