I'm embarrassed to admit that I've played a role in writing and designing PowerPoint presentations that were simply too much.
Too many points, too many pages, too many complex graphics. As hard as I try to simplify the presentation, someone (frequently multiple someones), along the management chain of command feel compelled to add a few more points.
The end result is a bloated presentation that wanders around for dozens of slides before reaching the final point - long after everyone in the room has started day dreaming.
We could all have more success in our sales pitches -- for money, for partners, for new business, if we followed Guy's 10/20/30 Rule of PowerPoint.