To put it in layman’s terms SEO is simply the process of first telling the search engines what you are about and what you want to rank for, then going out and earning those positions.
Why you need it is simple, Google is the biggest decision engine the world has ever seen. People make buying decisions based on Google searches every day and the percentage of those people who do grows constantly. If you have been in business long enough to remember how important it was to be in the yellow pages then think about it like this. Google is 10 times as important to your business as being the first listing in the yellow pages ever where. You are cheating yourself out of business growth by not taking action.