OPINION: Mills on ... Kit Kat.

We hear a lot these days about the need for agencies to produce a Big Idea (remember, it's mandatory to cap up the first two letters when talking about this). Too often, however, the Big Idea tends to be a small idea inflated with a lot of hot air.

Now Kit Kat is not a brand that you would think needs a big idea. With 47 bars eaten every second, it is Britain's number one countline Indeed, some might say, it is already underpinned by a big idea in the shape of the 'Have a Break ... Have a Kit Kat' line which has been in use since 1957.

It's true to say, nevertheless, that the idea of linking a snack to a break is generic. Equally, however, I would argue that Kit Kat shows that if you stick consistently to an idea, no matter how generic, and build that idea into your advertising DNA, you have every chance of making it your own. You just have to look at Mars Bar's recent gyrations around its positioning to see how Kit Kat has effectively denied its rivals room to manoeuvre.

But the thing about all big ideas, especially 46-year-old ones, is that they need nurturing and, from time to time, updating; hence this new ad from Kit Kat which introduces us to a 'break philosopher' and trails Nestle's call for the entire country to have a 15-minute break at 3pm on 21 March - which is what you might call A Very Big Idea. Promotions and a flurry of other advertising activity starting from 17 March will build to that aim. You can imagine the PR that will ensue.

With all the rumours surrounding Mars' plan to launch a new product called Take a Break, it's easy to conclude that this is just a response - albeit a massive one - to the perceived threat. Not so, according to Nestle, which says that this is all about re-establishing and contemporising the break idea. According to its own research, Kit Kat advertising was in danger of falling into one of two traps: either people could remember the ...