Sales experts believe that in a market that is no longer expanding, the best sales strategy for a company is to pursue the largest market share, and the best way to achieve the goal is to do some comparative advertising that can highlight the shortcomings of competitors  In the depressed domestic milk powder market, A brand milk powder and B brand milk powder have been in a comparative advertising campaign for two years, accusing each other of harmful effects on the health of babies
However, these advertising campaigns did not increase their market share, but caused many people to stop buying any brand of domestic milk powder
Comparative advertising should not be used in a market that is expanding or is likely to expand