“There were two Santas at school today,” said my five-year-old. She was just coming to the end of her first term at school. My pleasure in hearing Santa had come calling was rather tempered by finding out there were two of the old fellas. How could they mess up so badly? They’ve ruined it for all those children. What do I tell her now? Before I could collect my horrified thoughts, she piped up again. “One of them wasn’t real.”

This happened years ago but it stuck with me, because of what it shows about how we see the world. As Mark Twain said, “It ain’t what you don?t know that gets you into trouble. It’s what you know for sure that just ain’t so.” Now think about what you know for sure about your market, your customers, your business, your brand. Was it ever, really, so? Is it still so? Things change – and that creates opportunities.

Think of the familiar gripes you hear in focus groups. Or from friends. I’d pay more to get it faster, to have it delivered, for someone to assemble it for me, not to have to wait in line. Why can’t I have it cheaper? Make a simpler version, it’s all I need. It?s easy to dismiss as the same old stuff people always say, before you get to the good stuff, the real purpose of the research, the thing you want to hear about – a new product, maybe, or some new advertising, or a new pack design.

But to other people, that throwaway warm-up chat is gold dust. Why? Because it inspires disruptive innovation. While the established airlines were refining their in-flight food and entertainment to justify the prices people were complaining about, South West and Easyjet and Ryanair got rid of it all, to give people cheap air travel. While Ford and GM offered ever-bigger discounts on new cars, ZipCar dispensed with car ownership altogether, realising some people don’t care about cars, they just want to be able to get around.

Ford and GM’s biggest barrier was their current business model. Those huge production lines have to be kept running. The main job of marketers is to help fill them. Who in Ford is going to champion an idea that might shut some of them down? By proposing a radical alternative to the current business, you’re betting against the company – what Harvard Business School professor Clayton Christensen calls “the innovator’s dilemma”. You could call it career suicide.

Most businesses are alive to this challenge now. You just have to say “Eastman Kodak” – who held patents for digital photography but didn’t want to harm their film business. There are solutions for the innovator’s dilemma, like separate innovation teams, or running parallel competing businesses, or by being watchful of upstarts and buying them. Zipcar was acquired not by a motor manufacturer but by Avis car rental.

But what if you don’t even know you’re filtering out the awkward realities? That’s the Santa Claus effect. Are we seeing the world as it is, or as we believe it to be? That’s where marketers have a critical job to do. It’s our responsibility to listen, without fear or prejudice, and to share what we hear. There’s plenty of talk about bringing the voice of the customer into the organisation, and even into the boardroom. Our challenge is to make sure it’s the true, uncensored voice, not the convenient voice. If you can do that, your business may not get everything it wants for Christmas. But there’s a good chance it will live happily ever after.