Though major ad agencies are reluctant to try mobile marketing, countless opportunities await the less skittish, according to a new report by ABI Research, writes ClickZ.

The report forecasts advertisers will spend $3 billion on mobile ads by the end of this year, including for ad-supported entertainment content such as videos, music and games - as well as search ads.

By 2011, ABI said, the market's value will reach $19 billion, including mobile search and video advertising. It predicted that mobile marketing spend related to video would surpass SMS by then, and that spending on "broadcast mobile video" ads alone would hit $9 billion.

ABI also said mobile marketing will become a crucial part of the marketing mix due to its highly personalized nature, allowing brands to reach out to consumers in unique and useful ways due to location-based services, among others.