Market research firm Gartner Inc. has released a study that finds global mobile spending will reach $18 billion this year, up about 37 percent from $13.1 billion last year.

Beyond that, the market is expected ramp up dramatically, reaching almost $42 billion by 2017.

The delay off the line comes from supply growing faster than demand, says Gartner, but in the later years of the study period, standardization, data and greater brand-side interest will fuel rapid growth.

Mobile display ads are the single biggest category of ad format, says Gartner, and will stay that way throughout the study period. The display category will shift to mobile Web display, however, after several years of higher app display growth. Mobile video advertising will also grow quickly, driven by the tablet market.

Local advertising, buoyed by local search and map ads, will grow as more mobile data is gathered from users as they opt into being located automatically or by using geolocation apps.