Businesses frequently use customer surveys in an attempt to improve sales and increase profits. However, a recent study of the effectiveness of these surveys found that among a group of businesses that sold similar products, profits declined in most of the businesses that used surveys during the course of the study but not in most of the businesses that did not use any surveys during the course of the study.

Which one of the following, if true, most helps to explain why the profits of businesses that did not use customer surveys did not decline while the profits of those that used surveys did decline?