I recall a few years back producing a major gifts/planned giving brochure for a very large health system in Pennsylvania.
The VP decided to do the 20,000 piece mailing in-house. The brochure was accompanied by a cover letter that they produced, with each letter and matching #10 envelope addressed to a Dear Mr. and Mrs. Problem? All 20,000 recipients were medical school grads, so it should have said “Dear Dr. and Mrs.”
Well, not really. After I calmed down Mr. VP-Gone-Mad, he received 6 unpleasant complaining letters next week, each one loaded with a mighty check ($1000 to $6000).
The entire mailing had a 27% response rate. To this day I do not know why. But please, don’t try duplicating this error deliberately!