As any business owner who's ever watched "Mad Men" knows, advertising is designed to change consumers' behavior and attitudes. These changes don't always have the intended effect, though, and changes in consumer behavior can yield both positive and negative consequences for advertisers.
Most businesses advertise to increase their customer base and profits. The obvious positive outcome is that your business makes more money and can keep up with increased demand. A wildly successful advertising campaign isn't always a net benefit, though. If you don't have enough employees or sufficient supplies, a sudden uptick in business could yield unhappy customers and an increase in expenses as you hustle to produce.
Public Images Changes
Advertising can change your public image. A commercial that apologizes for a mistake in the right way might encourage angry customers to come back, while one that sidesteps blame or responsibility could make the situation worse. Advertising campaigns that push hot-button political issues can lose you business, and some advertising decisions -- such as making women feel bad about their bodies or encouraging children to buy a potentially dangerous product -- can yield boycotts and significant negative media attention.
Relationships With Other Businesses
The way you choose to advertise your business can affect your relationships with other businesses. If you mock another business's product, you might find that the business owner is hesitant to speak with you and employees don't want to come work with you. Likewise, defying or openly vilifying an industry standard could have a negative effect on your relationship with similar businesses at the same time it could cause other businesses to join and respect you.
Advertising costs money, of course. A poorly designed campaign might still bring in enough funds to compensate you for your expense, but a defamatory or otherwise illegal campaign could cost you money in fines, penalties and legal fees. Ideally, though, a well-designed campaign that captivates customers could leave you flush with cash if you have the resources to deal with a sudden increase in business.