Even if you are not a follower of American football, you will have heard of the controversy surrounding Nike's choice of a sporting ambassador - Colin Kaepernick, the footballer who knelt during the playing of the American national anthem in protest at racial injustice.

There could not have been a more controversial figure as the face of Nike and many boycotted the brand. But Nike is a sharp-thinking brand and will have worked out that those people are probably not their core audience. Nike clearly sees its engaged customers as belonging to a demographic, mostly young people, for whom racial issues are a specific concern. And in evidence, their sales in the US rose by over 30% after the ad featuring Kaepernick was aired.

The tagline "Believe in something, even if means sacrificing everything" resonates with young people. They want their brands to be known for something, even if it is not universally popular.

Benetton used to occupy the controversial space, not being afraid to use AIDs or racism as themes for ad campaigns. And whilst many accused them of using the plight of others to promote their clothing, Benetton believed the brand should reflect the real world and not a vanilla version.

And I think that is what Nike has done well, it is promising to stand for something real not an imagined version of life. And that is what appeals to young people looking for their brands to have a social purpose.