For me the best way to promote the site is to do link building for proper optimized keywords.Writing articles like this one and submitting to article directories is a way of spreading your message across the net.Social bookmarking sites can be an brilliant way to promote your web-site.
I think there are a these best way of promoting a web sites In first Search Engine Optimization then Social book marking forum posting , Blog posting and Social web sites. These are famous and useful way of current way of promoting any web sites.
We can promote a website by doing Search engine optimization. By optimizing keywords of the website, google indexes our site and page rank increases and SERP also increases. And Main thing to promote a website is based on managing the reputation and brand image. This involves several processes like link building, blog commenting and so on.
I do seo & smo both. But i always try to get good quality backlinks from high PR or thematical websites. I prefer quality not quantity. And there all lots of activities we can perform to generate backlinks.