The state of the market right now:

In 2007, mobile marketing reached just under $3 billion. The majority of the increase in spending will be through SMS or MMS messaging campaigns.

The prediction for the future:

Text messaging is expected to remain the highest ad placement for marketers because of emerging markets in Asia and India which do not support video, display and other mobile campaigns. Messaging is expected to account for more than $14 billion of the total $19 billion spent on mobile campaigns by 2012. Messaging campaigns accounted for $2.5 billion in mobile ad revenues in 2007. Text-based ads have a response rate of more than 10%.

Read more at BizReport.