Sherwood was speaking on the subject of "Achieving integration on a global scale" at a seminar staged by mergers and acquisition advisers Results International covering emerging markets and digital communications.
Admitting multinational clients are tempted to save money and achieve consistency by running globally integrated campaigns, Sherwood said he did not think the rise of digital platforms would necessarily help integration.
"Clients always say that they want a big unifying idea that means the same to consumers around the world ... If you are a brand owner the next challenge is to find the right mechanics to spread the idea across the globe."
Part of the challenge lies in variations in digital media consumption between different countries, especially the difference between those where mobile penetration is strong versus those with broadband computer connections.
Sherwood illustrated his point with reference to BBH's work on Lynx/Axe and a British Airways social network concept called Metro Twin.
Metro Twin was launched last year as a website to link London and New York, giving frequent travellers between the two cities the chance to recommend places and sights and swap tips.
When the concept was extended to link London with Indian city Mumbai recently, BBH had to change the website approach for an experience optimised for mobile phones that would cater to India's much bigger pool of mobile users.
Sherwood advised clients to consider "What mechanics and channels are available? And how are these platforms used in the target market? If you are working on a six to eight month development cycle a lot can change during that time."
This article was first published on brandrepublic.com