> A lesson I learned is that if the topic is interesting enough you can skip the intro and jump straight in to that material, and if you combine that with a joke you can capture the audience's attention just fine.

This is important in sales as well.

I hate getting a sales pitch where they tell me the history of the company. Big Japanese companies are the worst in this regard for some reason.

For each slide, imagine the audience is going to get up and leave unless you give them a reason to read the next slide. You don't need to justify your existence if I don't really know what you have to offer.

Plus it's all about me (the listener) not you (the presenter).