For Sir Martin Sorrell, the WPP chief executive, size can be a mixed blessing. On the one hand, it gives him the clout and resource to attract Unilever's pan-European media account, worth one billion euros, into its MindShare operation.
On the other, avoiding conflict becomes a perpetual problem. Indeed, some commentators have asked whether, in taking Samsung's global brand marketing assignment, WPP is cutting itself off from too much other potential business in the sector.
Moreover, with WPP set to rival Omnicom as the world's largest communications group, it is bound to be exposed to all sorts of headaches. If it's not the demands of Brussels, it's in creating a church broad enough to house the likes of Procter & Gamble and Unilever.