Ogilvy, the writer. Ogilvy, the farmer. Ogilvy, the spy.

Anyone who works in advertising knows about David Ogilvy. He had worked as a chef, researcher, even a short stint as an amish-styled farmer, before embarking into founding his own advertising agency with only $6000 in his pocket.
At O&M david wrote headlines about Rollce Royce's loud clock, which subtly told us the engine was silent, he introduced the original "most interesting man in the world", which was the man in the Hathaway shirt. He wrote books like Ogilvy on advertising, he dabbled in subliminal advertising by getting a hypnotist to deliver the message but decided against ever running it.
But did you know that David Ogilvy was a British Spy?
David Ogilvy - The Farmer and the Spy.

Ogilvy’s experience with Gallup was particularly valuable to Stephenson, who commissioned a series of polls to analyze U.S. public opinion toward Britain. The results countered isolationist doubts of British ability and will to win the war. Ogilvy’s report, with its cumbersome title, “A Plan for Predetermining the Results of Plebescites, Predicting the Reactions of People to the Impact of Projected Events, and Applying the Gallup Technique to Other Fields of Secret Intelligence,” showed how polls could assess the true strength of political movements in different countries and guide British policy. Although neither the British embassy in Washington nor the London Secret Intelligence Service (SIS) went along with the report’s recommendations, General Eisenhower’s staff later did pay attention and successfully carried out polls in Europe as Ogilvy had advised.
Ogilvy’s basic job, says intelligence expert Richard Spence, was to spin or spike polling information considered harmful (or helpful) to British interests. BSC wanted results that would steer opinion toward support of Britain and the war—front-page stories that showed people were more interested in defeating Hitler than staying out of war—and make sure the polls told people what they wanted them to hear. Espionage work sounds more romantic than it was, Ogilvy conceded later in life, although it did have its cloak and dagger side. He sometimes came home from work with a briefcase handcuffed to his wrist.
His effectiveness in targeting pro-Axis operators led to him join the BSC team that helped the United States set up a foreign intelligence service—it had none—that became the Office of Strategic Services and today’s Central Intelligence Agency. “At one point, I was giving OSS about 80 reports a day from my sources,” said Ogilvy.