If you're anything like me, the first bit of the brief you look at is the 'proposition box.'

And the second question anyone asks you after "what are you working on?" is "what's the proposition?"

Meanwhile, within the agency, everyone endlessly debates 'what the proposition should be' and whether a certain proposition is "interesting" or "crap."

But recently I've started to wonder if the proposition is an out-of-date concept, that might be holding us back.

The proposition derives from Rosser Reeves' USP, which he developed in the 1940s. It tends to lead to what I call 'benefit amplification' communications...e.g. 'light' products that float in the air, 'easy to use' products that allow the consumer to relax in a deck-chair, or 'great value' products that allow the consumer to buy lots of other things with the money they've saved.

Frankly, I think it's old hat. And I bet consumers are getting tired of it too.

The worst sin of the proposition is that it's static, and the second-worst sin is that it's hard to get it to lead to modern, interactive communications.

Nowadays I'm trying to think more in terms of 'brand purpose', aka 'brand philosophy' or 'mission' (if you have a useful distinction or preference between these terms, let me know).

A brand purpose, as defined by Jim Stengel (former chief marketing honcho of P&G) is “the brand’s inspirational reason for being. It explains why the brand exists and the impact it seeks to make in the world."

Examples: Method expresses its purpose as "People against dirty." Google's mission is "To organise the world's information and make it universally accessible and useful."

The advantage of a brand purpose - in my eyes - is that it's far more active than a proposition. It's more interesting, and it has inherent momentum. And you can get consumers to interact with it. Who wants to interact with 'value' or 'time-saving'? So basically, I believe it is more likely to lead to better, more modern work.

Also, it's probably a more powerful selling tool too. “People don’t buy what you do, they buy why you do it,” as Simon Sinek famously said.

The latest Nike TV ad - the best commercial I've seen in the last 3 months - is a great example of a purpose ad. Nike's always had a purpose. It's not a brand built on a proposition such as speed, strength or endurance. It's a brand built on a mission, to inspire athletes.

So that's where I'm at. Propositions are out. Purposes are in. What do you reckon? Who's with me?