SAN BRUNO, CA: YouTube, the video platform owned by Google, is set to offer independent verification of the viewability of ads that run on the site, according to reports.

The Financial Times said that YouTube had succumbed to pressure from advertisers wanting greater transparency around this issue amid concerns that they were paying for ads that weren't being seen.

The industry standard is that at least half of a video ad must be on screen for at least two seconds. The reasons most video ads are not seen are that they end up running in a background tab while users focus on something else or are scrolled off screen or abandoned in less than two seconds.

Earlier this year Google reported that average viewabilty rates across the web were 54% but claimed the figure for YouTube was 91%.

But now it intends, by the end of the year, to let independent verification groups – yet to be named but these could include the likes of comScore and Integral Ad Science – access data on the position and context of ads shown on the site, people familiar with the plans told the FT.

Google would only say that it was committed to meeting its clients' measurement need and that it was "taking our clients' feedback into account as we continue to roll out new solutions".

The need to take action became crucial earlier this year when it emerged that Kellogg Co, the cereals company, was one among several businesses said to be cutting spending on YouTube precisely because of the lack of independent verification.

Aaron Fetters, director of Kellogg's global insights and analytics solutions center, last year outlined how the company had successfully linked viewability – in this case of online display ads – to increased sales; more recently he said: "if we can't measure it, it's hard to justify the investment".

Unilever, the FMCG group, has been at the forefront of a push for 100% viewability of digital ads, with its criteria for video ads including that a person must click to start it rather than having it play automatically, and then they must play at least half the ad with the sound on.

Keith Weed, chief marketing officer, welcomed any moves that led in this direction; ultimately he hoped to see "100% viewability through third-party verification across the industry".

Data sourced from Financial Times, Advertising Age; additional content by Warc staff