Ask for a sample of 2,000, instead of the proposed 500, to permit regional breakouts of the results. Your copy or art is going to be exposed to focus groups. Go to the groups yourself. Insist that the opportunity to learn is so great that you must attend the discussions. Once you are in the observation room behind the one-way mirror, play it cool.
Groups are strange animal-like organisms which have a mind of their own.
They are very unpredictable and usually uncontrollable. Get some hard liquor out and quickly mix drinks for the clients. Encourage them to drink up. Get them new drinks the instant their glasses are empty. Tell dirty jokes.