A reader sent me this:
"Here’s how to use a keynote speaker. Tell them you want them to talk to 10% of the people attending the retreat prior to their speech, and then to summarize their findings as the top three ideas or action items that would benefit this company. If the speaker isn’t excited by this process, pass - no matter how many best-selling books they have or how good your friend said they are."
I'm doing just that in a couple of weeks.