I read a really good article by Jeff Sexton on grokdot.com. Yeah, Billy could get on your nerves with his booming voice but there's no denying the man's ability to pitch a product and convince a lot of people to buy it.
I think Jeff sums it up nicely when he wrote, "What Billy knew that so many of us forget, is that a conclusion that the audience comes to on their own is a conclusion they’ll believe and act on. No normal advertising claim can achieve that, no matter how much evidence you throw behind it."
You can read the rest of his post at http://bit.ly/60TN9.