According to ABI Research, the market for advertising on mobile devices will hit the $3 billion mark by the end of the year, and will climb to $19 billion in just four years. But only if advertisers, carriers, and marketing companies follow every avenue offered by mobile technology.While mobile marketing may be just finding its legs here in the United States, it's more mature in Europe and Asia. Forward-thinking brands, companies, and advertising agencies in the U.S. are really just getting their feet wet with mobile advertising campaigns. With mobile advertising being so new, finding which types of campaigns are most effective across different market segments has yet to really be determined. Banner ads, SMS alerts, MMS alerts, and full video commercials placed in and around mobile video services are just a few of the avenues being explored.

For all its unanswered questions, money is still being funneled into mobile advertising. ABI expects the bulk of mobile advertising dollars to be spent in the mobile broadcast arena, which will reach $9 billion by 2011.

"Mobile advertising and marketing is a risky, albeit enticing business," says principal analyst Judith Rosall in a statement. "Unlike the PC, a mobile device offers a uniquely personalized communications channel. Carriers worldwide have quite a bit of information about their end users: name, sex, age, geographical location. And depending on the handset and plan their users have purchased, the carriers probably also know something about their economic status and credit record. But they don't like to release this information to third parties because they want to protect and control their customers."