Bursting the SEO bubble...
Myth - SEO gives you better rankings...
Busted, I have never done anything other than use proper tags and keywords in the HTML to get any site I have touched in the top 10 results. You DO NOT need to fight for pole position nor pay a listing engine to improve your ranking. A whole industry exists preying on peoples ignorance of how the internet works.
Myth - People searching won't find you without SEO
Busted, utter rubbish, what do you think web crawlwers are for? When you publish a page, as long as you have set your host up to submit a web page to Google search engine then your page will be crawled for contents and keywords extrapolated from that and your page can then be found. It can take anything from a few minutes to a few hours to propagate through the internet, it is very big so don't expect miracles.
It matters very little how you set up your domain, if you want to make your visitors ability to remember URL's then fine, I personally don't, that is what "Bookmarks" are for after all...
You will find raging arguments all over the net on this subject and having sat on the fence for many years watching the arguments on many subjects ending up in petty kindergarden squabbles, I go with the philosophy of what best fits your purpose, you will find some occasions SEO is better than untidy and use of proper META than not. It is really down to your needs, if a web page is going to be static and not change then for sure, put the effort in to making it a persistent resource, if your page is going to be fleeting and constantly changing and morphing, then SEO is really going to be a strain on the crawler and you may find that people like Google won't bother crawling as often.
Basically, don't do it just because you have been told to do it, look at what and how you implement your website and does SEO fit your needs.