For 12 years, Adam Smith has inhabited a kind of twilight world at Zenith Media and then ZenithOptimedia. Divorced from the day-to-day business of TV planning or buying for clients, he has instead been studying global advertising and media statistics and programming facts that are pulled together to create ZenithOptimedia's now-famous publications.
Every agency should have a character like Smith but they are in short supply. His publications, most prominent being the quarterly adspend forecasts (covering 60 markets) and the wryly written ZenithOptimedia on TV book, have created untold PR and exposure to global clients for a network that, until recently, struggled to compete on the global stage.
Last week, however, Smith announced that he is to leave his Paddington base (he is the head of knowledge management at the agency) for a new role as the futures director at WPP's Group M.
The aim is to create market-leading research and publications for Group M that will span the entire marketing services world. As one agency source mischievously suggests: "I think Sir Martin Sorrell was being forced to use ZenithOptimedia forecast figures so he went out and bought the man who wrote those figures."
The group nature of the task, across three global networks, and access to in-depth research from WPP companies such as Kantar and Millward Brown were the big attractions of the role.
Smith is an interesting character. Very tall and well-groomed, he's not an archetypal media man. Described by more traditional colleagues as "mad as a hatter", he broke into media in 1989 as a TV buyer at Zenith after seven years as an international steel trader. This followed a law degree from Oxford.
He has since added an MBA and a diploma from the Chartered Institute of Marketing. And he is a mine of music and television programme trivia.
On being told where Campaign's offices are located, he responded with: "Is that opposite Colet Court? The building features in the opening credits of The Sweeney."
As well as being a forecasting expert, Smith can lay claim to being an exceptional writer. He has published a book, The Beatles' London, which encapsulates his fascination for music and the aforementioned ZenithOptimedia on TV publication is a quarterly labour of love.
His extra-curricular writing might be on hold for some time though - as well as a new job, Smith has recently become a father for the first time and is renovating his new house.
From late January, he will be based at Group M's new offices (it is taking a floor of the old Carlton building on St Martin's Lane). So after so long at ZenithOptimedia, what was the attraction of Group M's new operation?
Smith says: "In my view, WPP is the best diversified marketing services company - I'll get exposure to emerging markets where traditional advertising is still cutting edge and to a breadth of marketing services businesses."
He doesn't say it but you suspect any frustrations that might have surrounded the ZenithOptimedia role were linked to the focus on media and the lack of context that could have been provided by access to other Publicis Groupe companies. It's not surprising, though, that ZenithOptimedia so jealously guarded its crown jewels in terms of the branded reports.
Smith says of the new role: "I won't know until I'm inside but I'm not going there to whisper in Sorrell's ear about strategy. They want a forecasting brand and to raise their game in that area."
At ZenithOptimedia, Smith and his team were responsible for more than ten periodicals. Critics would argue that WPP has acted too slowly in launching properly into the global forecasting market, that the glory days of market leadership in the area were captured by Zenith Media and the market will now be flooded with "me too" products.
Smith argues that the challenge is to take forecasting to the next level.
"Traditional media value is just half the story, the marketing services side of things is less well measured. I want to get a handle on the whole story - the size of the whole market and the sense of diversification between media spend and marketing services. There's a sense of holy grailness about this."
Kelly Clark, the chief executive of Group M in Europe, the Middle East and Africa, backs this argument: "Adam was the obvious person for this role - he's committed to building a leading offering in this area and he's got experience and ideas on how to add deeper context to marketing services forecasts."
Smith also says that there's an element of "refreshing myself" after 16 years as a buyer and then a forecaster at Zenith. He says he loved the autonomy of the role and the global perspective it brought but it was time to move on.
As if to prove the global nature of the forecasting business, he's off to finish the latest set of figures to be unveiled the following Monday by Steve King, the worldwide chief executive of ZenithOptimedia, at a UBS conference in New York.
Soon enough it will be the likes of Sorrell and Clark who will be benefiting from such endeavours. But Smith's impact at WPP could well depend as much on co-operation between its companies as on his ability.
THE LOWDOWN Age: 44 Lives: Putney Family: "partner" Maria (ex-Zenith) and son Sam, born Sep 7th In three words: tall dark gruesome Treasured possession: The alternate Abbey Road cover shots Favourite book: Lucky Jim by Kingsley Amis Alternative career: Keeper of the Queen's Conscience Motto: Again, in plain English please