90% of affiliate posts on YouTube and Pinterest are not communicated to users, according to US-based research into commercial disclosure among influencers on both platforms by Princeton University.

Publishers using either YouTube or Pinterest may include affiliate links in posts, particularly when working with brands to promote their products in association with the content being shared. Publishers then receive money from the brand when a user clicks on the affiliate link.

However, the study found that of the 3,472 videos (0.67%) on the social video platform and 18,237 pins (0.85%) on the social photo app containing affiliate links, just 10% were adequately disclosed according to FTC (Federal Trade Commission) regulations.

The three predominant methods of signposting commercial content in the study – including disclosure phrase links (e.g. #affiliatelink); explanation disclosures (e.g. “This video contains affiliate links, which means if you click on one of the product links….); and support channel disclosures (e.g. “AMAZON LINK: Bookmark this link…) – are not enough to fully disclose the relationship according to the regulatory body.

Instead, publishers should make their motivations clear using a short phrase that clearly states when publishers are being paid when an affiliate link is clicked according to letters sent out to content creators last year by the FTC. This is especially important given that posts with affiliate links were found to drive more user engagement, and therefore gain the benefit of each site’s algorithms in terms of placement.

The findings come as users increasingly questioning the transparency of paid relationships with publishers and brands online, with 88% believing they should be made aware when an influencer is being paid to promote branded products. Meanwhile, it’s easy to see why influencers would look to fly under the radar with 48% of consumers in the UK claiming they would avoid clicking an affiliate link to prevent an influencer from making a commission on a sale.

The research by Princeton University highlights the importance social media platforms play in how affiliate links are signposted, referencing YouTube’s paid endorsements tool and Instagram’s paid partnership branding feature on sponsored posts.

“Such disclosure tools are a step in the right direction, however, it is unlikely that such blanket disclosures will cover all marketing strategies,” said researchers.

“Future work could investigate what kind of affordances should be designed into social media platforms to enable affiliates to disclose clearly.”