Leveraging its position as owner of the fourth-most-visited smartphone properties, Amazon might become a formidable rival to Apple in the mobile-ad market. Amazon has hired Microsoft's Jamie Wells to build a mobile-ad sales team and is rumored to be talking to mobile-ad network partners such as Jumptap. More important, Amazon builds and sells its own mobile platform: It has sold 5.5 million tablets since the holiday debut of the Kindle Fire, according to IDC.
Startup companies attending this week's Stanford Accel Symposium explored "The Future of Advertising in Digital Media." Companies reported strong growth in a market that is still new and open to experimentation. Smaller companies are working to stay a step ahead of Google, which has yet to transition its online advertising power to the mobile world.