According to the International Sign Association (ISA), your sign should:
Attract new customers
Brand the business
Create impulse sales
According to the U.S. Census Bureau, every year 18.6% of the population relocates. This means every year there are new, potential customers in your area. The easiest way to gain these new customers is with signage.
"Top-of-the-mind awareness". This when your business is the first to come to mind when a customer is thinking about a product or a service. When we think about athletic appareal, who comes to mind? This is created and then reinforced by repetition. Constantly exposing your customers to your signage and having that signage designed in a way to compel their attention each time they pass the sign.
Your sign should be designed in a way that the customer can readily gather the vital information at a glance. It should also be recognizeable to the customer as well, this means not constantly changing your brand image. The most important thing is that the potential customer should be able to understand immediately what you are selling.
Signage and advertisement is the number one way to promote your business and enable it's growth. If a potnential client does not know where your business is located how will you get them in the door? Not only is having a sign important the look of your sign is important as well. As a customer, if you were to choose a hospital based only on their signs would you choose the hospital that had a plain white background with generic black text or the company that has a metal lettering, with lighting behind the letters? By adding style to your sign, you are more likely to attract the attention of a potential customer. Here are a few links that give information and statistics on the importance a sign is to a business.
The following are a few links about the importance of signage.
The ABC's of Signage information courtesy of the International Sign Association.