If we don’t have content for a long thing ( a meeting session, a performance, a speech, etc ) we can think of it as promise and fulfillment. Making a promise of some great reward in an hour can be big. The easy solution is to make smaller promises. Divide an event up into segments that can be completed with a good feeling. Instead of “I’m going to tell you an hour long story that will be worth your time and will illustrate productivity” … try “I’m going to tell you a couple stories, then I’m going to give you some principles, then I’m going to give you next actions.”
The theme / thesis is the same, but the content is divided. It’s not about short attention spans. It’s about short attention spans for unworthy content.
If our content is really sucky, we can break it up into tiny chunks. As long as the people know that we’re going somewhere with it.