There are many methods to promote your website. First of all your site should be search engine optimized with proper title, description, keywords etc. Use alt tags to all images and optimze its loading time.
Now your site is ready to get indexed by search engines by placing your site URL on high page rank sites and afterwards it needs promoting by writing articles,posting blog comments, using forum signatures, using google ad-words, paid text link etc.
Once your site develops fairly a good number of backlinks, there is no need of paid advertisement. It shall drive search engine traffic of its own forever.Beware to sell a quality product only.
Success of your Website promotion campaign depends to a great extent on the success of your Link building efforts. As Quality link building not just helps you build links but goes a long way helping you stay ahead of your competitors.
Much of what I've read so far in this thread encourages the SEO newcomer to find trendy ways to link the shit out of his web pages regardless of the caliber of the content. To throw webpages together then seek reinforcement outside the work in order to make the pages appear to be important is, to me, lame, usually not very effective and does nothing to offer the Internet anything new of any real value.
As a matter of fact, link building schemes don't normally in themselves sustain high rankings in competitive keyphrase environments. It is always best to concentrate on enhancing the visitor's experience by deploying high caliber, original, well-optimized content on web pages that exceptionally, but naturally, make full use of the optimizable web page components.
Focusing on delivering unique web content and working with that which is within your control (the on-site ranking factors) ensures the search engine that your webpages are important, credible and worthy of a visit. Focusing on link manipulation indicates to the search engine that you feel your webpages inadequate to compete with web pages that are naturally important.
Examine your keyphrase competitors. Some have high caliber content with little or no outside support while others stand the test of time on their own.