This response was provided to a reader who questioned how to effectively work with high profile speakers, especially those who have handlers that often seem to "muck- up" the process:
A common misfortune in event execution is when a high profile speaker dictates or detracts from the purpose of the event. That purpose is normally to persuade the assembled group to go out and perform certain activities in an expected manner that will benefit the event host, such as a change in job behavior among employees or taking a step in a prescribed sales cycle among customers and prospects. A "big name" speaker is almost always a draw, but is not a guaranteed advantage once people are assembled and in your seats.
Many speakers I work with, including the famous and powerful, are happy to support your agenda if you find and call to their attention a nexus between their views and your objectives.
When I worked with Walter Wriston, legendary Chairman of Citicorp years ago, or George Will the columnist, the approach was the same. I read their writings and speeches for the past six to twelve months, identified their talking points that helped position our speakers and proof points in support of our overall objectives. When we met, I presented them with a range of "ideas" they might emphasize in a presentation, paying great respect to their ideas as a basis. I also presented the purpose and goals of our event, and a block diagram of the agenda, explaining exactly how and where they fit into the overall plan.
Generally, speakers and their support staff (speech writers, etc.) will be surprised and impressed with the preparation and direction provided to them and will be willing to craft something that becomes a powerful part of your program. Speakers will often thank you for making their job much easier. Speakers tell me the reason they sometimes give a canned speech is lack of any direction to the contrary.
There are exceptions, notably those speakers who insist on giving the same canned speech at every appearance. Their value is usually their celebrity. Hire them at your own peril. If you do, preview their talk and be certain that no part of their presentation will conflict with your agenda and identify the points they make that support your objectives, and can be reprised in presentations by your other speakers.
Entertainers are an exception too, although a similar brief has worked wonders on many occasions.