Then again, the visitor might find you (due to the SEO), but not the "competitor", hence, the sale goes to you. There needs to be a balance. Great SEO can be done without paying a significant price design and content wise. In fact, it is content that can give you the SEO edge.If you focus on SEO instead of content and design, you will find that your long term customers will instead turn into visitors on the competition's site, and if they have better content and design you just lost a customer.