NEW YORK: Mobile adspend in the US will increase to $65.87bn by 2019, accounting for 72.2% of total digital adspend, the latest estimates from eMarketer have shown.

That represents a significant trend, given that mobile accounted for about a quarter (24.7%) of digital adspend in 2013 and just under half (49%) in 2015.

In terms of total media advertising expenditure, it also means mobile would have grown its share from 6.3% in 2013 to 28.6% in 2019.

Next year will be the tipping point when mobile adspend surpasses desktop, according to eMarketer, which predicts mobile will take 60.4% of all digital adspend with mobile spend valued at $40.5bn.

The shift to mobile ad spending is being driven mainly by consumer demand as American adults increase the amount of time they spend on their mobile devices. This increased by 32 minutes in just one year between 2013 and 2014.

In terms of format, eMarketer estimates that by 2019 mobile display adspend will total $33.9bn compared with $28.41bn spent on mobile search.

Interestingly, the report also expects US mobile ad spending on classified, email and lead generation to more than triple over the forecast period from $962m this year to $3.32bn in 2019.

Turning to spending on mobile apps, eMarketer says advertisers will spend $20.79bn on mobile apps in 2015, up from $13.67bn in 2014, which is also three times more than the $7.93bn that will be spent on mobile web browsers.

Finally, ad spending on mobile app installs is expected to reach $3bn this year, no less than an 80% year-on-year increase from the $1.67bn estimated for 2014.

However, eMarketer cautioned: "The leading search providers are making strides to attract app developers' ad dollars, but we expect app install ads to represent an insignificant portion of mobile search spending in 2015."

Data sourced from eMarketer; additional content Warc staff