I had heard the following phrase from customers many times: "This is just marketing. I don't have time for this." On the Web, people are developing banner ad blindness, but they are also developing marketing-speak and communication-spin blindness.
Web design: clarity is more important than persuasion - article by Gerry McGovern
In his article, Gerry references an article by an online market research company, marketingexperiments.com, who offer lots of free articles and resources arising from their work.
Clarity trumps persuasion: How changing the first seven seconds of user experience drove a 201% gain - marketingexperiments.com