Before we’d heard of the notion of social proof, we’d seen it in action and given it a name. Or rather one of our research participants had. The topic was new book publishing, and in a six-week project, he had the following brilliant insight. “You maybe hear a book reviewed on Radio 4, and then before you forget about that, you see a Tube ad for the same book. And you go, oh right, I heard about that a couple of days ago. And then you see someone reading it on the bus, and then you think ‘Oh wow, it’s everywhere. I need to buy it.’ But it has to be three times. It’s the power of three.’

What made it more powerful was the apparent randomness of the encounters – it didn’t feel orchestrated. It was a case of everywhere he turned, that book was in front of him.

The message in all of this?  Ideas need to be seen multiple times in different ways.  With new launches in particular, create diverse campaigns that foster the impression of serendipity – it’s so much more powerful when it feels like a personal discovery than a marketing onslaught.