A keynote speaker gets 25 minutes.

During those 25 minutes, hundreds of people stop working, producing, and selling. Add the cost of the venue, production, travel, and choosing the right speaker becomes a consequential decision.

I spoke with ten conference organizers about what separates a great keynote speaker from someone who merely owns a microphone. From what I have learned, here are eight tests for finding one:

• Real issues. A good keynote addresses one of the audience’s top two or three business or life priorities. Otherwise, people will start scrolling through their phones.
• Credibility. The business world is littered with “experts” who have assembled a talk from a few books. That can work. But a speaker with direct leadership experience or credible research—ideally their own—is far more likely to make an impact.
• Audience proximity. Listening to an astronaut or a wingsuit diver can be inspirational. But when the distance from the audience’s real life is too great, people go home inspired while thinking, “That’s not me.”
• Keynote speaking—not just speaking. Many people enjoy jumping onto a stage and talking, often slide by slide. Keynote speaking is different. As in an opera or a play, the speaker must hold the audience’s attention from the first second for 20 or even 45 minutes—through stories, strong transitions, surprises, pauses, and tension at exactly the right moments. This takes weeks of writing and rehearsing—and a speaker willing to make that investment.
• Fresh content. Even the best speakers can fall into the trap of repeating the same talk for years. It may still be powerful, but eventually it will bore both the audience and the speaker. A professional speaker researches the audience and meaningfully adapts the talk and creates at least one major piece of content for every event.
• Practical tips. Talks are nice. What people really want are two or three things they can apply tomorrow morning.
• Paid to perform. Plenty of speakers will come for free because they have a product or service to sell. That’s legitimate, but it creates an implicit tension. Their first priority may not be the conference—but themselves. Free speakers can add value, but mix them with professionals.
• Real feedback. Conferences and speakers know they may not work together again for months or years; few conferences hire the same speaker two years in a row. The best speakers don’t leave it there. They ask for honest feedback because they want the next keynote to be the best one they have ever given.

Many people can speak. Few can create a moment an audience remembers—and then turn that moment into action.