SEO requires patience and well planned strategy.
SEO requires making friendship with the bots - give them what they like feeding on..:)
Specifically, keywords at the back-end and front-end. The marriage should be natural and must make sense.
Secondly, redirects + SEO syntax - Meta Tags, Meta Description (150 Characters is good enough, not more and loaded with keywords, again sensible meaning)
Then comes in submissions - Articles + Blogs + Blog comments + Press Releases + Classifieds + Directory submissions + Social Media bookmarkings. All these are just but the necessary arsenal to go for good rankings.
Lastly to gauge how your website is being taken care of - Google Analystics + SEO SERP tools + Alexa + Dmoz (its submission website, missed it earlier so mentioning it here) + Quantcasting and much more.
Jump into the ocean, take the best route - no need to explore every uninhabited island which could be just a waste of time.
As SEO comes under Internet Marketing if you are doing that its mean you are doing everything and sure you will get the output from this. But you can not sya that SEO is enough one this is the one part which support in internet marketing to achieve the best.
SEO is technique which is improve our website ranking, popularity, visibility, and visitor on the major search engines like Google, Yahoo, Bing etc. As per my experience SEO is more useful for a website.