Yes it definitely does. In fact the only websites that do not need to do SEO/SEM are personal (hobby) websites. If you are a business, and it looks like you are from your website, you have to HAVE TO do SEO. Unless, your website is used just for the sake of identity.
Also, the very reason why you are here today, is because of SEO
Also, the very reason why you are here today, is because of SEO