The entertainers deliver a monologue. They share their knowledge and follow a script. Their goal is to impart wisdom. They don't bother to find out about their audience. It is all about them. They make you want to go back to school.
The connectors engage the audience members in the presentation. They make you part of the act - they ask questions and build a comfortable dialogue. They tailor their presentation based on your level of knowledge and neither talk down to you or over your head. They make you the star and as a result you will buy whatever they are selling.
Think about how it feels when you have excellent service. That's the feeling you want to create when you give a presentation. Don't be an entertainer - be a connector. If you will always focus on what the audience needs and put yourself in their shoes, you will succeed.
I'm still trying to figure out where these guys keep their PowerPoint slides when they're pouring. Maybe they're behind the bar.