Most people that I have met that are good at humor don't come off as "funny" when you meet them, except [ Amalgamated Chief Creative Officer] Eric Silver. 

A lot of people try to use humor, and it's just not funny, there's nothing more painful than that . Then there are people who can write funny jokes but then they just slap the product on at the end. Or they talk about the brand in a very boring way and slap a joke on at the end. In that case, all you remember is the joke, it has nothing to do with what you are trying to communicate. That isn't that hard to do. 

Doing the opposite of that is the hard part. Starting with the brand you are advertising and crafting a selling message for a specific client, that is entertaining to watch. The humor comes from the ad message, so you remember the message and not just the joke. The people I like to work with can take whatever tiny parameters a client gives us -- 'On sale for $19.99 until Monday' -- and they find something entertaining to say about that message.

I've always believed you have to give something back to people if you want them to listen to your brand message. Humor is the same thing. You actually like a brand, not Facebook like, but really like, a brand when they make you laugh. So the next time Kayak has something they want to talk to you about, you'll stop and listen because you like them.

When a client tells me that they are a serious brand and humor is not appropriate, I think of two things. First, if you took a poll and asked people what is the most trusted, reliable name in business, I bet FedEx would be at the top of that list. FedEx built that reputation with the help of smart, insightful humor. And then I remember when Mayor Giuliani asked us at BBDO, two weeks after 9/11, to create a campaign to get people to visit NYC again. He didn't say make tourists feel safe or patriotic, he said make them smile again.