Long before PowerPoint (or Keynote, or Prezi or…), telling your story, making your pitch, or teaching a class involved the art and skill of figuring out the flow and delivery of your message…orally.
IF there’s a time to speed up, a time to slow down, a time to pause before or after a key point to improve attention and impact when you’re speaking…
…THEN, why not do the same with what you’re showing?
The idea that you should “change slides every minute” is arbitrary.
The idea that “a 30 minute presentation should have <this many> slides” is equally so.
For your audience, attending your webinar or webcast or virtual class is a psycho-social shift. Even if you have your beautiful self on camera the audience will pay greater attention to your slides than when you’re mano-a-mano.
Improve attention and impact. Think “pace and pause” with your slides. Avoid dumb rules.