And most of the time, the mild-mannered chief executive has been more than happy to comply with a donation of his time, a few well-chosen words or a rousing speech or two.
However, he may feel that he should be a little bit choosier in future after he had a bit of a torrid time with a rather militant female comedienne who interviewed him for an as yet unnamed documentary about body hair - female body hair, and its removal, to be precise.
Now, the industry veteran probably believes he could handle any tough questions about advertising with intelligent, well thought out and insightful answers (after all, Haines is a regular contributor to Campaign).
However, he was probably a little less confident when asked to theorise on the issues of whether hair equals beauty.
For some reason, the researchers on the show decided Haines would be the ideal person to defend the Western practice of females shaving their body hair, so he was pitted against a fast-talking interviewer who staunchly believed women should not have to shave their hair to look beautiful.
However, Diary is thankful the TV company didn't step down Leo Burnett's hierarchy and opt to use the agency's consistently rude managing director, Paul Lawson.
It's fair to say much of the footage would probably have ended up on the cutting-room floor.