LONDON: As many as one in ten digital ad placements are blocked from being served on unsuitable websites according to soon-to-be released research.

Integral Ad Science, a company supplying media evaluation intelligence and technology, said that 11% of ads it monitored in the UK were stopped from appearing on sites alongside content that advertisers deemed inappropriate, Marketing reported.

The issue has gained prominence following a story in the Sun newspaper which said it had found ads for leading brands, including British Gas and O2, on sites "devoted to paedophilia, incest, bestiality and racism".

A recent survey suggested that marketers have not been greatly worried by this aspect of programmatic technology.

When Infectious Media polled senior marketers across Europe in February, they were most concerned about a lack of transparency around financial matters (65%) and the complexity of the ecosystem (55%). Issues around brand safety were mentioned by only 25% of respondents.

That attitude may now be changing given the adverse publicity. As MediaPost noted: "It's one thing to be embarrassed by being seen on a 'paedo' site, it's quite another to realise that your brand name is financially supporting it."

Niall Hogan, the UK managing director of Integral Ad Science, said this highlighted the need to work a content verification vendor, adding that he was aware of "many instances where buyers only choose to use the basic monitoring tool set because they feel that the full suite is cost prohibitive".

But he argued that the full costs were not that much greater and could prevent a much worse scenario.

"We are talking about a difference in pennies in the CPM here, not pounds," he said. "I am sure that each of the brands singled out in the [Sun] article would happily pay a small difference for the full blocking capabilities of the technology now."

The UK's Joint Industry Committee on Web Standards awards brand safety seals to companies that declare and independently verify how their processes minimise the chances of ads appearing next to inappropriate content.

Data sourced from Marketing, MediaPost; additional content by Warc staff