A recent report by eMarketer provided some good news for small business owners already using mobile marketing technology - the study projected that the number of American adults who access the internet from their mobile phones will increase from 73.7 million in 2009 to 134.3 million in 2013.

This growth is partially enabled by the technological advances and surge in popularity of smartphones; according to the International Data Corporation, smartphone shipments are expected to increase by 3.4 percent in 2009, and grow at triple the rate of feature phones next year, eMarketer cited.

Mobile internet use has begun to transform the way consumers think about their phones, with a recent Pew Research Center study finding that almost as many people said their mobile devices are "very important for getting online information on the go" (46 percent) as said that they were very important for staying in touch with other people (50 percent).

"Mobile access strengthens the three pillars of online engagement: connecting with others, satisfying information queries, and sharing content with others," said John B. Horrigan, associate director of the Pew Center's Internet & American Life Project and principal author of the report.

Small businesses should consider tapping into this demographic for high marketing returns on investment, experts advise.