They certainly do things differently at Media Planning Group. All the other major planning and buying networks have become thoroughly Anglo-Saxon, with a pronounced US twang - and it's true even of agencies with a French heritage, such as Carat, or continuing French ownership, such as the Publicis Groupe outfits. The last vestige of a French accent at Optimedia - once upon a time the figurehead Publicis media brand - was lost when it was subsumed into Zenith.
But MPG continues to be unapologetically perverse in its determination not only to look French but to sound Spanish. And, it's also the only media network that survives as a family fiefdom - as the unveiling of its new chief executive underlined last week.
Alfonso Rodes Vila is to succeed his brother, Fernando Rodes Vila, who had held the top job since 1994, when he replaced their father, Leopoldo Rodes Castane.
This, the family's fans say, gives the network stability and a homely feel. But, some observers counter, there's a huge downside too. With no need to bust a gut to keep their place in a corporate hierarchy, or impress anyone, come to that, the family tends to be somewhat aloof.
They're not exactly secretive. You can't place them in the same league as, say, the UK's Barclay twins, who currently own the Telegraph Group. But they're hardly communicative either. Within the network, senior managers exhibit impressive levels of loyalty to the Rodes family - no-one, they say, can fail to be impressed by their quiet charisma and understated intelligence - but it's hard to find anyone who's anything but hazy about who these people really are.
For instance, senior advisors fall over themselves to apologise for the fact that Alfonso will not be available to talk about himself or his new appointment, pleading that we make the most of the press release. The closest it comes to daring revelation is the statement that "Alfonso is 44 years old, lives in Barcelona and has three children".
Cynics go so far as to say that, as Alfonso (who was previously MPG's boss in Spain and southern Europe) takes the helm from his brother, the transition will be absolutely seamless. Outside the agency, Fernando had zero profile. So will Alfonso. Insiders say this is desperately unfair, though they do concede that, in the past, the focus of the network has been on Spain and Latin America, where the network is very strong. Tellingly, one insider refers to MPG as "the Spanish-speaking world's MindShare".
That's about to change, though - and it will be one of Alfonso's priorities to raise the agency's game in northern Europe, particularly the crucial UK and German markets. He will keep an office in London, as did his brother before him, but perhaps he'll be just a little more visible. In the interim, we have a classic example of the Great Gatsby effect: in the absence of established fact, lurid speculation fills the void. You can, for instance, find people convinced that the Rodes family is built on old money and is the embodiment of Catalonian aristocracy.
Others tell you that in fact Leopoldo was a self-made man who launched a full-service agency called Tiempo in 1965 (now part of the BBDO network) and spun off its media department as a standalone company called Media Planning in 1978. This, in turn, was acquired in 1999 by Havas, which merged it with its existing media brand, Mediapolis, to form Media Planning Group.
What is not in doubt is the fact that the family now claims membership of Spain's plutocracy - a small and highly exclusive club if ever there was one. They are inordinately rich.
"In Catalonia, they are like royalty," one source confirms. They are, some say, the powers behind the throne at Barcelona Football Club (it's not easy to prove either way: the club is not noted for its management transparency) and were important members of the committee that produced Barcelona's winning bid to host the 1992 Olympics.
In summer, they tend to head for the Balearics, where the family estate in the Mallorcan hills is not a million miles from King Juan Carlos' Marivent Palace; and during August - the high point of the island's social calendar - neighbours include Michael Schumacher, Michael Douglas, Catherine Zeta-Jones, Eva Herzigova and the tennis superstar Rafael Nadal.
Those who have visited say that senior Spanish politicians seem to be regular guests; so if Tony Blair wishes to swap Italy for Spain, as he contemplates his next budget holiday, he knows who to talk to. Strangely, though, perusal of our well-thumbed back copies of Hola! has yet to yield up any mention of the family.
That could genuinely begin to change though, especially if the Havas chairman, Vincent Bollore, propels MPG from a European backwater into the big league - and it's telling that Alfonso's promotion to the top MPG job comes only because Fernando was elevated to chief executive of Havas in May.
Bollore gained control of Havas largely thanks to the votes of the Rodes family, which had held Havas equity since the 1999 takeover. There has been speculation that Fernando's appointment was not just a reward for that help but is also an indication that Bollore is now ready to take control of Aegis (where he has a stake just shy of 29.9 per cent) before merging its media properties with MPG.
So the two brothers might find themselves very much centre-stage in the weeks to come. Those who know them say we will warm to the brothers when (or if) we really get to know them. But, we are warned by MPG insiders, the family and the agency are always likely to retain a distinctive approach.
As one insider puts it: "Profile for profile's sake is just not important to the brothers. They're not the sort of people to go out seeking other people's approval. We all know people in the ad business who are moderately well-off and incredibly flash. The Rodes brothers are extraordinarily wealthy, but they are the least flashy people you could ever meet. And they are astonishingly well-educated. They do things differently and MPG is proud of that difference - the beauty of the network is the way in which it allows local managers to manage."