Back in the late 80s, early 90s, Honda Corp came up with a simple strategic mission statement: “Six Hondas in every garage” All of Honda’s R&D, manufacturing, marketing, and sales plans supported this mission.
I am not quite sure how a mission statement gives you credibility.
Do you read a contractor’s mission statement before you give him your rehab project or do you rely on references from his prior customers ?
A track record gives you credibility. After each deal you close, ask the seller to give you a testimonial letter. A few of these letters will give you all the credibility you need.
References are definitely important. I believe that Mission Statement presents the values the individual or company go by or rather live by. So I do believe that while its not the main stake in establishing credibility its a important piece in the Reference book.