Previous liaisons with Asda and WH Smith both ended unsatisfactorily. Will an account such as KFC, a potentially awkward alliance between the fast-food chain's franchisees, the company's UK marketing department and the US owner, Yum! Brands, be any different? In short, can BBH do "down and dirty"?
The answer is almost certainly yes. The fact is, Asda and WH Smith arrived too early in BBH's development. Not only has it learned some painful lessons but today, no-one can afford to be snooty about retail.
The move of so much work out of the retail "ghetto" operations and into creatively potent shops such as BBH reflects the complex, fast-turnaround and labour-intensive nature of so much current business.
A former senior BBH creative recalls how Asda and WH Smith threatened to "swamp" the agency. Today, the agency is unlikely to be overwhelmed by a similar account.
Gwyn Jones, BBH's managing director, who was there when it split with Asda in 1989, says: "At that time, the Asda account was very different to any other in the agency. Now that kind of complex and high-volume business isn't markedly different from the work we produce for a number of our clients."
Nevertheless, accounts such as KFC are tough for agencies to get to grips with. Burger King, the closest comparison, is a triumvirate of the highly influential franchisees with their own views on how the brand should be promoted, the UK marketing operation and the US parent with a global strategy to pursue. Its relationship ended abruptly with Lowe, an agency with creative standards not unlike BBH's.
"This is a very ad-responsive market in which a price offer or a sales promotion can have an immediate and dramatic effect," an agency chief with extensive experience on fast-food business explains. "But it's also a sector where few players have an overall brand idea."
In BBH's favour is its relationship with Claire Harrison-Church, KFC's marketing director and the former head of marketing for Lever Faberge's Lynx, which has been handled by BBH for almost eight years. "That relationship will help, but a lot will depend on what sort of grip she keeps on the marketing function, which gets put under a lot of pressure from franchisees," an industry source says. "If she can, that's fine; if not, the agency is screwed."
Jones dismisses the notion that KFC is markedly different from any other client. All clients are influenced in their decision-making by a wide range of people, from shareholders to dealership owners, he says.
KFC, meanwhile, is laying down aggressive expansion plans with 400 new UK outlets due to open in the next five years. Its optimism is fuelled by the health scares, which have tainted its competitors but are also increasing consumer preferences for white meat.
But what about all those opinionated franchisees? "It's like dealing with car dealers - not always the most pleasant of experiences but all part of the job," Jones says.