BusinessWeek has an interesting story about mobile advertising and the threat that it poses to Google:
As more people use cell phones and their tiny glass screens to gain access to the Internet, Google and its fellow online advertisers will have less space, or what's called ad inventory, to place marketing messages for customers. Google makes money selling ad inventory. And its ad inventory is diminished on a cell phone.
What does the future hold?
Consumer use of mobile Internet in the U.S. has longed trailed Asia and Europe, where standardized cell networks made it easier for handset makers to produce gadgets that tap the Web at blazingly fast speeds. But in the summer of 2007, Apple rocked America by launching the iPhone. The computer maker wasn't the first to put the Web on phones, but for many consumers, the iPhone made the experience more robust.
Almost two-thirds of Americans have had some experience with mobile Internet use, and the adoption trend is most pronounced among teens and young adults, according to Pew Research Center. About 60% of adults 18 to 29 use text messaging every day, compared with only 14% of their parents. Nearly one-third of young adults use mobile Internet. This is the future, because people take their media habits with them as they age.