Zenith is 20 years old this month. Looking back from this distance, it is extremely difficult to imagine the impact the formation of the first media superpower had, and continues to have, on the way media agencies operate around the world today.
In the 1980s, media was either handled by the media departments of full-service agencies, or media independents such as Ray Morgan & Partners and TMD. Zenith Media Buying Services broke the mould in 1988, when Saatchi's John Perriss conceived and launched the first so-called "media dependant".
This new-look bulk-buying operation was a conglomeration of the media buying departments of several full-service agencies in the Saatchi and Saatchi Group and one of the bigger media independents - Ray Morgan & Partners. In many ways, it was a forerunner of what WPP has put together in modern times with its GroupM buying operation.
It is often those who come along in the second wave who truly prosper, after the pioneers have blazed a trail and made the mistakes for everyone else. That's why the "media factory" in Paddington has taken on legendary status: many of media's biggest names cut their teeth at Zenith before going on to bigger and better things elsewhere.
Zenith has had its tough times over the past two decades, but it was also the first agency to bring bulk buying to the US and Asia, and is now a fully established part of Publicis Groupe's global advertising empire. The Percy Street operation is very different from the grim Paddington offices, but there is continuity between the two, especially in the form of worldwide chief executive Steve King, who has been at Zenith for all of the agency's 20 years.
Having spoken to many people involved in Zenith at the start and who worked there over the years, what comes over is an incredible enthusiasm for their time at the agency and the formative influence it had on media and their individual careers. It was a phenomenon that will never be repeated.