Philip Hartmann, head of content at Coca-Cola Germany, gave the warning during a panel session called The New Era of Influence, hosted at Ogilvy & Mather Group UK's London office.
Hartmann said Coca-Cola had moved from simply paying social media influencers to promote its products through placements to setting up its own YouTube channel, CokeTV, with influencers as hosts. This allows them to interact with the audience, he said.
"This dialogue is really happening, and it’s happening all the time, which is fantastic, especially for young people who are a bit bored of advertising – people forcing them to buy products. All of a sudden they feel part of it, they are part of the community – it’s their YouTube."
Although product placement "still works", paid media are seen as "not authentic", he said.
He added that if brands want to reach out to teenagers, "it’s much more important that people speak directly to them on an eye level, that it’s authentic, that you don’t bullshit them, that there’s a real interaction".
Helen Lawrence, head of creative agency development at Twitter UK, said new research by the social media platform found that if a consumer saw a branded tweet, their intention to purchase a product increased by 2.7 per cent. If it was promoted by an influencer and a brand, intent to purchase grew to 5.2 per cent.
The two ‘influencers’ on the panel – Jamal Edwards, founder of the music channel SBTV and Sarah Mikaela, a fashion blogger with 115,000 Instagram followers – also stressed the importance of authenticity in brand collaborations.
Mikaela admitted she had her "fingers burnt" with collaborations where it was not the right fit for her. "Authenticity is the most important thing," she stated.
Edwards said he had also been approached with collaborations that did not seem authentic.
"I didn’t go through with it," he said. "I try to do stuff that relates to my audience."
A study yesterday showed that a large number of influencers were not aware of the UK advertising regulator's requirement to flag sponsored campaigns as such, and that a small number were being encouraged by brands not to do so.