The new five-year outlook for U.S. mobile local advertising from BIA/Kelsey is, in a word, optimistic.

According to the research firm, total U.S. mobile ad spending will grow from $790 million in 2010 to $4 billion in 2015. During the same period, BIA/Kelsey projects the local portion of that total to increase from $404 million to $2.8 billion.

This makes locally targeted mobile ads 51 percent of overall U.S. mobile ad spending, growing to 70 percent by 2015. Consistent with other local media, BIA/Kelsey defines mobile local advertising as that which targets users in specific locations or contains location-specific calls to action.

Among the drivers of mobile ad revenue growth are smartphone penetration, mobile Web usage and related increases in ad inventory. BIA/Kelsey expects this to come about as large brand advertisers evolve their campaign objectives to the capabilities of the mobile device — most notably, location awareness.

The firm also sees mobile advertising moving down market to small and medium-sized businesses through a combination of local sales and self-serve tools. Exploding mobile usage, clearer ROI and a shorter purchase funnel will accelerate this demand within display, search and SMS advertising formats.