“Gartner said it expects global mobile advertising spending to reach $18 billion this year, up from the estimated $13.1 billion in 2013. By 2017 it’s projecting the market will have sized up to be worth $41.9 billion.”

Key points:

• Video will show the highest growth — with the category being driven by tablets and growth in tablet ownership.
• Gartner added that it expects the display category to shift to mobile web display after several years of higher growth in in-app display. 
• Search/map ad types –  Gartner expects them to benefit from increased use of location data gathered from mobile users opting in to location services or proactively checking in to the places they visit via their use of apps such as Foursquare and Pinterest.

Mobile Ad Market Spending To Hit $18BN In 2014, Rising To ~$42BN By 2017, Says Gartner | TechCrunch