Web Usability & website Promotion (SEO) - what’s the relation?

Is there a relation between Web Usability and search engine optimization?
Does this blog puzzled you as the title reads web usability and website promotion?
Is there any interconnection?
Yes, Web Usability and search engine optimization and web promotion are interlinked. By Web Usability we mean good Content, easy Navigation, easy Accessibility, less Downloading Time, Systematic Arrangement, etc more simply it means Usable website. If a website incorporates all these features any visitor will find it userfriendly and so does the search engines. Think about Search Engine as a visitor. If it could download the page in very less time, could find keyword stuffed good content, could easily navigate throughout the site, then it will give more priority to such website compared to similar themed websites which lacks in user friendliness*. A user
would like to revisit a good user friendly site often so does any search engine because both likes such site.
So if you want your website to be search engine friendly then first you should make it User friendly, follow the basic Web Usability concepts and then promote it, get links from other sites to your site so that it is easily reachable too.
Good Web Usability is the foundation of Search engine optimization or web promotion.
* Above comparison is based on assumption that websites in discussion have same backlinks (Links from external websites).