Credibility
"The reader will notice if you are putting on airs. Readers want the person who is talking to them to sound genuine."
William Zinsser, On Writing Well, p. 20.
"Credibility is just as fragile for a writer as for a President. Don't inflate an incident to make it more outlandish than it actually was. If the reader catches you in just one bogus statement that you are trying to pass off as true, everything you write thereafter will be suspect. It's too great a risk, and not worth taking."
William Zinsser, On Writing Well, p. 78.