The NAB's latest "breakup" marketing exercise aims to hit three targets: make a political point, differentiate NAB from other banks, and get customers to think about moving to it. It hits the first target dead-centre, might hit the second, and leaves the third still oddly untouched. As a political statement, it's timely and powerful. It's a statement not about party politics, but about the politics of banking. The Big Four suffer from the strong perception they are a cosy gang, comfortable with each other and dismissive of the rest of us. Governments and Oppositions, consequently, have begun a competition to see who can do most to rein them in. NAB chief executive Cameron Clyne rightly sees the public dislike of banks, and the political reaction, as a great danger to the industry. And he has sensibly decided against the strategy of dismissing critics as revolutionaries and fools. Instead, he's decided to announce a "breakup" of the Big Four. He's done it cleverly and cheaply, using street theatre and stunts to capture the attention of news bulletins, YouTube and Twitter. Clyne's timing is perfect, because competition between the Big Four is now stronger than it's been for some time. The four all fear their quarter-century of easy growth is over. Consumers are newly cautious about borrowing, and the Big Four have as much Australian market share as they're likely to get. So they're turning on each other. Deposits have become the battlefield. ANZ and NAB have axed mortgage exit fees. CBA and ANZ have improved their service in branches. The NAB pushed this dynamic along at the weekend by promising to pay mortgage exit fees for customers switching from Westpac or the CBA. The "breakup" campaign vividly reinforces the idea that banks are indeed competing hard. The veteran politicians battling daily over the future of the financial system understand the "breakup" campaign's political potency. Treasurer Wayne Swan and the shadow treasurer both voiced their approval loudly and quickly yesterday. Swan said: "It's about time we had a bit of competition". So will "breakup" differentiate NAB from the rest? Will the love-song CDs, helicopters, footpath chalkings, staged YouTube episodes and crooners on flatbed trucks make NAB stand out from the banking crowd? Certainly the campaign is fresh, adventurous and nimbly executed, breaking the taboo against discussing competitors. But beneath the fun lies a strategic problem. At root, the "breakup" campaign represents yet another Big Four bank claiming that it's not like those terrible Big Four any more. The ANZ rejects "Barbara From Bankworld", the CBA is "Determined To Be Different", and now the NAB has "Broken Up" with its rivals. Only Westpac stands alone, defiantly not-different. The "we're different" pitch can be very effective. But it works best when three-quarters of the market isn't making the same