The app advertising market is poised to grow at a rapid pace over the coming years, surging 136% from $27.1 billion in 2017 to $64.1 billion in 2020, according to a new market research study by AppsFlyer, the mobile attribution company.

The report projects that marketing spend will grow at an average year-over-year rate of 34%. Growth is forecasted to gradually decrease with time as the market matures but will be sustained by substantial increases in media costs and mobile usage, as well as the number of paid campaigns, apps available, and mobile users overall.

In North America, one of the world’s most predominant app markets, app install ad spend growth is projected to double by 2020 and hit $12.9 billion. Similar to the global projections, the average year-over-year change in this region will reach around 21%.

While growth of app installs driven by marketing activities will be significant in the coming years, the growth rate will not match the expected rise in media costs. AppsFlyer’s data shows global non-organic app installs will grow by 110% into 2020, while North American non-organic installs will increase by 73%.

With both the ad spend and growth rates of non-organic installs expected to maintain the same ratio through 2020, marketers will have to be increasingly efficient in their marketing efforts amid rising media costs.