Effective SEO is important to any business. The best practice for a really robust SEO is to have a shorter URL. The reason for this is that shorter URL's rank much higher in searches than a long complex URL. Shorter URL's are easier for end users to find and click on, and this is exactly what you are looking for when setting up SEO.
The largest search engine in the world currently is Google. High rankings in Google search is the prize of all practitioners of SEO. It is important to note that sites with shortened URL's consistently rank higher in Google search than those that are longer. Long URL's contain a ton of redirects and different folders that makes a for a inefficient end user experience.
Taking all of these factors in account, it is easy to see why shorter URL's are more effective for SEO. Higher Google Rank, easier end user experience, and SEO best practices all make it important for any business to have a shorter URL for their site.