Usually when there's a big media review called the agencies concerned respond with a mixture of optimism and fear. Unlike creative agency reviews, media agencies often keep the business as the numbers they use and the deals they can negotiate are pretty similar. Unilever, one of the world's biggest advertisers for brands like Dove, Surf and Hellman's, is reviewing its worldwide media - a maximum of £5bn no less. At the moment it uses agencies from WPP, Omnicom and Interpublic, with WPP's MindShare in the UK driving seat. So, in the normal course of events, all three biggies would fancy their chances of gaining some business. At worst they wouldn't be fired altogether. But Unilever is in radical mode at the moment with newish CEO Paul Polman, formerly finance head of Nestle, keen to cut costs. Which will inevitably mean slimmer pickings for the winner(s) and very likely fewer of them. WPP, which is facing pretty grim trading prospects on its own admission, will be especially worried. MindShare, its biggest media agency, has taken some hard hits recently and been shedding senior staff left, right and centre. A new battering from Unilever really would be a worry.