Mobile ad spend will grow from $13bn this year to reach $39 in 2018, according to Juniper Research.
The fastest growth will be experienced in in-app advertising, with the Indian subcontinent the largest growth region, increasing total spend by four times over the next five years.
More targeted in-app ads, perhaps done most effectively by Facebook to date, will help improve app monetisation, as well as the replacement of banners with rich media ads. Opt-in and incentivised campaigns will help ensure consumer buy in, while real-time-bidding will grow even further as it becomes the most efficient way to buy and sell ad space. 
“We are witnessing a change in consumer perceptions of mobile advertising as advertisers begin to use opt-in, or reward-style advertising,” said Sian Rowlands, author of the report. “By harnessing big data and location information, mobile ads are being better targeted to users.”
