The most valuable part of setting expectations is telling the truth, even if the truth means you don’t know, but are willing to find out. I am much more likely to remain a customer of companies that treat me with respect by setting expectations, and sticking to their word.
So true. Trying to set a false expectation or trying to cover up that you don’t actually know the answer may have short-term benefits, but in the end the customer will find out the truth. If you’re up front and honest with them from the start things work out much better.