But now. just as the global media agency brands seem to be making a fair fist of providing a consistently professional international service, the grand dame of them all has its skirts blown up to expose a chink or two.
ZenithOptimedia, the world's sixth-biggest media network and catalyst for the existence of the business, has a few thorny issues in a number of overseas markets following the collapse of its joint parent Cordiant.
The saga throws a spotlight on the fabric of the entire industry.
As the vultures line up to gnaw what meat is left on the Cordiant carcass, the otherwise trifling matter of four ZenithOptimedia offices is providing some interesting spice. As a network, ZenithOptimedia is 75 per cent owned by Publicis (after Publicis bought Zenith's co-parent Saatchi & Saatchi and merged it with its own Optimedia brand); Cordiant holds the remaining 25 per cent. Under the terms of the joint ownership, Publicis has first dibs on Cordiant's media stake should Cordiant wish to sell, or be sold.
But in Indo-China, Hong Kong, Malaysia and Argentina, the ZenithOptimedia offices are 100 per cent owned by Cordiant, with the name used on a franchise basis. So while Publicis does have first refusal on Cordiant's stake in the network, these four offices could pass into the hands of a new owner. Such as WPP.
There's even some speculation that Publicis' right to buy the 25 per cent could be open to interpretation and, armed with the best lawyers, a new Cordiant owner could challenge the stipulation.
For ZenithOptimedia, this seems a cruel irony after the battles it has already survived. Zenith has always done a masterful job of juggling its parents and making a decent show of coherence, whatever the tribulations of its owners. In fact, over the years, Zenith's management has often seemed stronger and more focused than rivals with a much simpler ownership structure but beholden to stronger creative siblings. Zenith may not have enjoyed much shared business with its flailing sister agencies Saatchis and Bates, but arguably their weakness was an odd blessing, liberating and goading the media brand.
And over the past year, too, the Zenith team has seen through the Optimedia merger with relative grace. Mercifully, piddling about with toe-in-the-water back-office mergers has been eschewed in favour of a decisive marriage with a clear positioning.
Now ZenithOptimedia must be hoping for a quick resolution into a single owner, although respect for the Publicis way of doing business is not high. Meanwhile, Sir Martin Sorrell will no doubt enjoy giving the grand dame some headaches should his bid win the day.