Now Playing: 03-30-12 Marketplace

In the last installment of "Robots Ate My Job," special correspondent David Brancaccio tells us what we need to do in order to promote jobs through technology and avoid violating Asimov's First Law of Robotics: robots must never, under any circumstances, harm humans. The Canadian government has decided to get rid of its penny. An oversupply of natural gas has substantially pushed prices down, altering the United States energy landscape. And we hear why the states matter in tonight's big lottery jackpot drawing.