The best humor makes a point, and accomplished speakers favor illustrative humor over jokes that liven things up but serve no real purpose. The best way to use humor effectively is to change the PEP formula—Point, Example, Point—to the PHP formula—Point, Humorous example, Point.
Winston Churchill once advised the Prince of Wales: "Use a pile driver and hit the point once, and then come back and hit it again, and then hit it a third time with a mighty whack." Speakers who use humor to reinforce their points make members of the audience focus in an entertaining way, without making them feel like they are being hit over the head repeatedly with the same point. Whether they remember the joke is not important. What they do remember is the idea that the joke illustrated.