NEW YORK: US publishers report that more than half of visits to their digital properties are coming from mobile devices but that these are contributing less than one fifth of digital ad revenues.

That's the case at the The Wall Street Journal Digital Network and a similar gap is evident at the New York Times Co. "[Mobile revenues] are definitely lagging audience. No question," Meredith Kopit Levien, the latter's chief revenue officer, told the Wall Street Journal.

Where mobile accounts for perhaps 20% of digital ad revenue at the Wall Street Journal sites, that figure is around 15% at those of the New York Times.

Targeting is a major issue, since the tracking infrastructure that has been developed over many years is set up for desktops and doesn't work at all well on mobile.

Andy Blau, Time Inc.'s group general manager, highlighted the difficulties: "We need to be able to help advertisers differentiate between people interested in buying mid-priced cars or expensive cars," he explained.

Unfortunately for publishers anxious to recoup print advertising losses, Facebook and Google are rather more adept at making such distinctions and are soaking up the greater part of mobile advertising dollars.

While some publishers have chosen to jump on the Facebook bandwagon, using its Instant Articles program to publish stories directly to the site, others are exploring alternative approaches.

The New York Times, for example, is to trial a new ad product that divides a day into seven parts and enables marketers to target messages to users in these particular "moments".

The mobile gap was also remarked on by Travis Johnson, global mobile head at IPG Mediabrands. "Consumers are so much more in this space than the advertisers are," he told

"We've got clients … seeing upwards of 50% of their site traffic come through from mobile devices, and they're dedicating 1% of their spend towards driving people there," he said.

"They're not optimising their assets and making the most of that," he added.

He suggested the gap arose since mobile was still a new space for IT, marketing and sales teams.

"It's almost a new piece of infrastructure to get all your assets aligned," he said. "It's taking a lot of clients quite some time."

Data sourced from Wall Street Journal,; additional content by Warc staff