While the current turmoil in Cairo may obscure the post-revolutionary optimism that pervaded the city last winter, that mood was powerful at the time. Despite the chaos in the virtual absence of government, the metropolitan region of some 14 million was taken over in January by an Arabic pop music video urging people to “go crazy” by committing acts of kindness to spread happiness. The film, produced by Coca Cola, features street scenes of people being kind and happy in well-known Cairo locations. Locals say it perfectly reflected the hopefulness and optimism of Egypt’s people as they embarked on the difficult path of building a new democracy.

This spring, when I spent 10 days working in Cairo, the catchy song was still on everyone’s lips. Asked about the video, Egyptians uniformly identified it as a local production — a combination of an ad, a pop song, a documentary and an accurate social commentary on post-revolution Egypt. Despite the truth of most of these observations, “Go Crazy” is part of a global campaign originated for Coke by Ogilvy Brazil.

The Coke campaign is one example of what three prominent co-authors addressed in a March HBR post titled “Great Advertising is Both Local and Global.” As they wrote:

“It’s hard to create relevant and timely global advertising themes, positioning, and stories that reinforce the brand, appeal to consumers around the world, and can be creatively delivered through all touch points… One solution to this tension is to pursue what we call glocal advertising strategy — locally adapting a universally embraced core idea that will resonate in any market anywhere in the world.”

Coke rolled out the “Go Crazy” campaign in numerous locales, including South America, Africa, the Middle East and the UK. In each place the central story was identical, but the executions were quite different in virtually every aspect — music, people, locations, focus.

When executed flawlessly, such global-local campaigns combine the power and efficiency of a single global brand with the targeted, culturally nuanced appeal of a localized execution. It’s not easy to do, however. The key question for global brands is, “How can marketers pull it off consistently?”

Click here to read the full post at the Harvard Business Review.