A graphic design firm would go through your complete business nature and goals before working on any particular design campaign for you. This would help it create the best designs for you that will surely yield results. Designs should always be used in the right proportion with the right mix of contents and other visual representations. While too less use of graphics may mar the web based goal of a site, too much use of the same would also return similar results. That's why expert designers should always be hired who have complete knowledge about the pros and cons of using graphics in a site.