Big ideas. They've been getting a lot of attention recently, and rightly so.

After all, engaging through compelling stories is as old as mankind itself. It's how we make sense of the world, and how we remember. And it's been the mainstay of the traditional marketing model.

However, with P&G's recent challenge to advertising creatives to "forget the tech and fall back in love with the idea" , it's important to recognize that technology has in fact changed the nature of the big idea forever. Otherwise, what seems big might just turn out to be bad. Three key changes:

1) Body language has become more important.

There's been an explosion in the frequency and variety of interactions between brand and customer, that technology has enabled. Some of this is deliberate, as marketers seek to keep customers actively engaged, in a world where the traditional sales funnel has been replaced by a dynamic, continuous customer journey. Some simply comes from the ease of making contact with companies now.

Regardless, every interaction provides an opportunity for customers to read a brand's body language, and sense what the company behind the brand is really like.

2) Word of mouth has been enabled.

Experiences can be spread more widely. What customers think and feel about a brand is informed not just by their own experiences of it, but also by what others have experienced. Technology has supercharged word of mouth, and the collective experience of a brand that forms is retained in the cloud.

3) Personalization is expected.

As customers interact with brands more, and in a variety of ways, they expect those experiences to be joined up, and relevant. If not, at best customers will conclude that a brand is not very competent. At worst, that it doesn't care about them.

Authenticity matters

In such an environment, how a brand is perceived is less about what it says, and more about what it does, and how it behaves. No longer can a big idea simply be a compelling story that creates an engaging image for a brand.

For example, Pepsi refresh might have been a big idea, but it didn't seem genuine or relevant for a soft drinks brand. BP's "beyond petroleum" eco-friendly platform certainly resonated, but was shown to be completely at odds with the culture of the company.

Today, a big idea has to spring from the values and beliefs of the company behind the brand. As well as compelling, it has to be coherent with how the company behaves, to be central to its operations, and delivered seamlessly across all the various touchpoints.

Otherwise, no matter how big it might be, customers will sense that it's fake.

And, in today's connected world, that's a very bad idea...