Short answer: If you have a website, you absolutely need SEO. The life and blood of a website are its visitors. If you don’t have any, your website is as good as dead. If you’re able to rank your website at the top of the search engines, you’ll benefit from a stream of traffic that won’t have click costs associated with it, and that won’t stop when ads are turned off. Rank organically, and you’ll enjoy 24/7 visibility.