"Start Small." "Wait." "Don't Mix." Those are some of the warnings Maureen Dowd did not know about. As a result, she overdosed on a marijuana-laced candy bar, an experience she made the subject of two recent columns in the New York Times. Dowd was a non-user -- even of medical marijuana -- who went to Denver to find out what legalizing recreational use was all about. That's territory that Justin Hartfield has been exploring since 2007 when he founded Weedmaps. Now he's the CEO of a $25 million company, headquartered in Irvine. He says he's perfectly positioned to become the "Phillip Morris of marijuana." We hear from him and from Mark Kleiman, Professor of Public Policy at UCLA and co-author of Marijuana and Legalization: What Everyone Needs to Know.