Last week I had some plumbing work done in my home and the plumber was a few minutes late for our scheduled appointment. When I called him to confirm that I had the right time on my calendar, he told me he was running late because he had just realized he had on a pair of shoes that did not match...prompting me to say "the leak in my basement does not care about your shoes."
I sense something similar goes on with sales people, specifically around what they do to "prepare" for a sales call. Assuming they do something to prepare, it is generally the wrong kind of preparation. They stare at the company's website, they read volumes of annual reports and perform countless hours of web searching hoping to educate themself about the prospect.
Spend your time preparing the questions you will ask your prospect that are designed to uncover pain. Spend time preparing questions around how long the pain has existed, around what they have attempted to do in the past to eliminat the pain and around how the problems they are facing are impacting their business.
You showing up and sounding like a Wall Street analyst or talking annual report does not matter...shoes might not make the man...they certainly don't make the plumber...but the right questions sure do make the sales person.