It is increasingly difficult to talk about the Internet, or media and marketing in general, without the conversation quickly turning to mobile phones.

How has mobile Internet so quickly become part of the consumer media experience for millions? Through a confluence of essential factors in mobile Internet adoption and use, mobile Internet reached a critical mass this year, offering a large and diverse enough base of users to support large-scale mobile marketing efforts.

This paper pulls from Nielsen's broad portfolio of mobile research to provide an overview of the mobile Internet market in 2008 and the opportunities it presents.

We look closely at the universe and demographics of mobile Internet users, their devices, the cost of accessing the mobile Internet in the US, the sites and categories that are emerging as leaders on the mobile Internet, the relationship of PC and mobile Internet consumption, customer satisfaction, network quality and the state of the advertising opportunity in the mobile Internet space.