Still not sure whether or not search engine optimisation is for you? If you haven't already then take this simple test:
Think of 3-4 search terms that a potential customer might use to find your company, product or service. Open any search engine(i.e. Google, Yahoo etc) Type one of the search terms you just thought of Where is your web site in the results? If you appear in the first 2 pages (or 20 results) for each search term then you have a well optimised site, if you don't see your results then chances are your seeing your competitors, and so will your potential customers!
This very simple test soon shows you if you need SEO or not. If you do, search now for free seo advice on the web - you need it :-)