With 2.5 billion mobile phones used around the world, mobile advertising is set for growth. London-based research firm Informa Telecoms & Media predicts within the next year that a sharp rise in mobile advertising will become noticeable to consumers. Furthermore, with the wider adoption of the mobile TV, according to Informa, mobile advertising market will hit $11.35 billion worldwide in the next five years. However, in order to reach the target, certain things are required, including consumer acceptance, handset compatibility, bandwidth (no)limits, interoperability and consumer protection regulations.
Red Herring has an article with more in-depth information.