This is a point made by famous advertiser David Ogilvy, in "Ogilvy on Advertising." Some ads have been proven by measurement to un-sell a product. The worst

This is a point made by famous advertiser David Ogilvy, in "Ogilvy on Advertising." Some ads have been proven by measurement to un-sell a product. The worst companies do a poor job of measuring the effectiveness of their marketing and un-sell their product. A good advertiser will measure for this affect and change their ads accordingly. But yes. Not all ads improve sales. Many ads do un-sell product.