Just take a look at the everyday responses to the questions about SEO. Then tell me how you can afford not to do SEO on your website?
When developing your link building strategy, a wider variety of sites linking to you is more important that many links from a small handful of sites. Search Engine Optimization, gaining rankings in google,bing,yahoo. So your website makes you money.
SEO is the forgotten little brother of website building, but without it you could be missing out on valuable visitors, which means even more valuable money, see the video for details.