A bad PowerPoint presentation doesn't even make for good nap time. Some one is always jabbering about something.
Dave Paradi has written an article about this problem.
"If we assume some relatively conservative meeting parameters of four people per presentation, a half-hour presentation on average and the wasted time due to a poor presentation is one-quarter of the presentation time, we arrive at a waste of 15 million person hours per day. At an average salary of $35,000 per year for those attending the meeting, the cost of that wasted time is a staggering $252 million and change each day."