Creating excitement for your event. A question I often get from my private clients is, “Do I need a headliner for my event—someone important that will draw people in?” Certainly everyone wants to have a great event and a “big name” can help with that.
However, the simple answer is “no.” Your mission can be the headliner. People come to your events because they were personally invited by someone and they want to support your cause.
If over the years, you've created an expectation that someone important is going to speak (and you can afford to pay travel and/or speaking fees) then continue with that tradition. But if instead, you can highlight the mission without an outside speaker (such as showing a new video or providing testimonials) do that instead. It makes the planning process much, much simpler, less expensive and you have better control of the messaging.
Just remember, while having a headliner there is nice, your mission is why people really come.