This is a multifaceted question and I'll give the short answer. They help to underwrite the cost of newspapers, television and radio stations which provide us with news and entertainment and they let people know what goods and services are available to the community often including when certain items are on sale and therefore a better value for the consumer. Advertising also drives customers to businesses which provide the goods and services to the community as well as providing jobs to the community. Without advertising it's likely that our choices as consumers would be less and that job opportunities might be lower as well.