Despite growing audience figures, publishers have revealed they are losing ad revenue.

Most recently, Will Harris, head of digital at Conde Nast, admitted that by focusing on the GQ magazine product on mobile, the publisher had lost ad revenue.

Speaking to the International News Media Association (INMA), Harris said: “Mobile was the number one platform our audience was on so it was going to be the number one thing we had to develop.

“The display ad space you had on desktop is gone so now you have less to sell, less space.

“If there is one upside it’s that mobile is an inherently personal device and if you are able to tap into that personalisation and know more about your customer you will be able to charge advertisers more to access the right people.

“If you want to talk to a specific segment of customers then you can charge a premium for that

“What we are trying to educate our advertisers about is that when it comes to impact, really the measure of impact is engagement."