Les Binet and Sarah Carter get a little bit angry about some of the nonsense they hear around them… like the appeal of reality advertising

Recently, we attended an advertising research debrief for a 'functional food' brand. This kind of brand is rarely encountered – the product had a real and valuable functional benefit. It was scientifically proven to 'correct' a common medical issue. The campaign featured real people who had used this brand, talking enthusiastically about how well it had worked. In theory, this campaign should have worked a treat.

Social psychology theory repeatedly describes the power of recommendation by 'people like us'. People in focus groups often enthusiastically suggest using real people like themselves in ads to help them relate to the ads and believe ads' claims. And we all know about the phenomenal success of 'reality TV' – TV programmes featuring real people.

But, you've guessed it. Our research debrief reported that the campaign message came through loud and clear. It clearly worked well to inform people. But unfortunately it didn't work very well to persuade people to try the brand.

Why was this? The first clue may lie in what has happened to reality TV.

When Big Brother started in the late 1990s, it was a pioneering social experiment which did actually feature quite 'real' ordinary people. The novelty TV format was intriguing and viewing figures were huge. But fast-forward a decade and we find the novelty has worn off. Nowadays any semblance of featuring real, ordinary people in reality TV has long gone. The Kardashians anyone?

The problem is that ordinary isn't very interesting. And that matters a lot. People don't watch TV to get information about our brands and products. They watch to relax, be entertained and chill out with their loved ones. They're mostly not very interested in brands – even when they really do work. So, if we're going to stand any chance of making an impression, we have to be interesting. And the trouble with ordinary people is, as our research debrief brutally reminded us, they can just be a bit too… well, ordinary.

Our campaign made the mistake of thinking that a cracking rational message just needed some real people testimonials and this would be enough to influence people. It rarely is. Informing is not the same as persuading. Persuasion is primarily emotional, with rational messages playing a secondary role.

Recommendations from friends and family can be highly influential, because we already have an emotional bond with these people. But recommendations from strangers are processed in a more nuanced way. On TV, they are often screened out. After all, your real may not be my real. And even if it is my real, most people don't want their own, rather dreary, reality reflected back to them when they settle down on their sofa after a hard day. Jim the car mechanic or Pat at her yoga class may have had a lot of success with this brand. They may be real and convincing. But are we interested? Does it emotionally move us at all?

Online, recommendations can have a lot of influence, but only for people who are already interested in the product and are close to buying. Even then, people have become very canny at sorting out which recommendations to trust and which to ignore.

So can we ever use real people? If so how? Maybe those Kardashians give us a clue. There are many examples of powerful creative work showing real people but, usually, they are wrapped in an emotional context which makes them far from ordinary. The amazing Paralympic athletes in Channel 4's 'Meet The Superhumans' campaign were real – but far from ordinary. The Sapeurs of Congo in the Guinness campaign were real – but far from ordinary.

Maybe T S Eliot was right. In advertising, as in life, humankind cannot bear very much reality.

This article originally appeared in the May 2014 issue of Admap. Click here for subscription information.