How do your customers find you on the web? Do they visit your website because you told them to go there? Are they typing in the right address? Are they even getting there at all?
If your main website visitors are ones that you are telling them your website address, what is the sense? If you can communicate with them and tell them your website address you should be converting them to customers instead of sending them to your website. The purpose of your website should be to find new customers. If you have a website built and don’t take into consideration Search Engine Optimization then what you are doing is spending a lot of money on a billboard, or an interactive Kiosk, but instead of placing this billboard on I-75, or the Kiosk in front of the food court in a busy mall, you’ll be placing your website in the middle of the woods. Without Search Engine Optimization no one finds your website, no one is going to accidentally stumble across it. Your only visitors will be the ones you send there.
Remember Search Engine Optimization (SEO) shouldn’t cost you anything. The cost of SEO is far outweighed by the return received from added business you will receive.