"E-commerce is 10 years old, but it is still in its infancy," eBay CEO John Donahoe said in a wide-ranging, hour-long interview last week. The four-year eBay veteran, who was named to succeed Meg Whitman as CEO in January 2008, has been on a 20-month mission to turn around the Silicon Valley icon, which popularized online auctions for millions of people worldwide. His efforts recently resulted in the first quarterly revenue increase at eBay in a year. E-commerce accounts for only 5% of all retail sales but will soar to 15% to 20% in five years, as more consumers conduct transactions via mobile phones and the Internet, Donahoe says. EBay anticipates more than $500 million in mobile-based application revenue this year, mostly through the iPhone. The eBay app has been downloaded more than 5 million times.