In this February 2008 presentation, David Marcus, founder and CEO of Zong, talks about the new business models created by mobile channels. Zong lets people use their mobile phones to buy virtual goods. The system is easy to use: enter your number, go through the verification process, and pay on your monthly cell phone bill. Zong, which works with 250 mobile network operators in 45 countries, was acquired in July by ebay, and David is now VP Mobile for Paypal.