TripAdvisor has unveiled a first for the travel advertising industry by launching a ‘Delayed Ad Call’.

In a move designed to increase the client’s confidence in the value of display advertising as well as the impact that it has on the way that online advertising is measured, partners of TripAdvisor will now only ever pay for advertising that is seen by a user on the site.

This initiative works by only making the ad call once a user gets to a point on the TripAdvisor page where the ad unit is in view.

Most online publishers - and therefore networks and trading desks - provide a very disparate environment with many ad placements per page which are often multiple times below the fold, in positions that a user never actually sees.

Martin Verdon-Roe, vice president global display sales, TripAdvisor said: “Our clients are always looking for measurable results and confidence in the media they are buying, whether that be for a Branding or a ROI campaign.

“With our delayed ad call in place advertisers can now be fully confident that the results that they are measuring on TripAdvisor are a real and true representation of their media investment.”

According to a study by AdSafe Media, half of ads bought directly on Publisher sites were never seen by the user, and 60 per cent of ads on Networks and exchanges were never seen by the intended user.

ComScore carried out a similar study which revealed that view ability ranged by format from between 66-74 per cent within the 12 Premium Publisher sites measured.

At the same time Comscore revealed a strong correlation between time-in-view and conversion, meaning that ads in view longer perform much better.

A spokesperson for IAB commented: “The IAB has formed a cross-industry group of experts from the buy and sell-side to review Viewable Impressions and discuss and surface the opportunities and challenges of such a move.

“TripAdvisor’s proactive move to counting an impression only when the ad comes into view is a bold market-leading position in advance of industry consensus in the UK.”

“The impetus for the discussions in the UK is the industry wide initiative in the US, Making Measurement Make Sense (also known as 3MS), which calls for a number of substantive improvements in digital media measurement, so that digital media are measured in ways which are compatible with planning, buying and evaluating in a cross platform world.”