But you aren't putting up a website to test the intelligence of your audience. You are putting up a website to sell your product/service. When you walk through a market you find vendors shouting out what they have on offer. They keep it precise: the item they are selling and the price. That is it. This is a tried and tested method of selling. One that humans have adapted to over generations. Tufte might have said that in the context of visualizations. Doesn't mean it applies to marketing as well.