While they are intended to prevent a company 's ads showing up on undesirable websites they are often ignored by marketers and digital agencies in programmatic ad buying , particularly if they are incentivised solely on delivery efficiency and reach . But mixed incentives aren’t the main contributor to ads appearing on these sites. Chris Horn , head of marketing science at Huge , said : " It 's a problem clients knowingly or unknowingly push their agencies into , and agencies do n't always have the time or resources to push back " .
While they are intended to prevent a company 's ads showing up on undesirable websites they are often ignored by marketers and digital agencies in programmatic ad buying , particularly if they are incentivised solely on delivery efficiency and reach . Chris Horn , head of marketing science at Huge , said : " It 's a problem clients knowingly or unknowingly push their agencies into , and agencies do n't always have the time or resources to push back " .