Until relatively recently, WEB2, social networking and blogging were unknown entities, and even after they were first launched online you would not have used them to advertise your website. Now they are a major means of enabling you to attain high search engine listings by rapid changes of content which search engines love and reward well.
WEB2 Sites
WEB2 sites are social network and social bookmarking sites, examples of the latter being Technorati, Delicious.com (formerly del.icio.us), Reddit, Blink, Furl and hundreds more. Social networking includes Friendster, Facebook, MySpace and YouTube and can be used both to attain links back to your website and inform others of your products, and Facebook has also recently launched their new Facebook Ads which are competing against Google's AdWords program. All of these can be used to advertise your website.
By registering with these sites you can not only include your websites in your profile on many of them, but also tag your web pages or even entire websites. Individual pages can be added to your social bookmarking sites at the single click of a button, and your web2.0 blog postings can be pinged to sites such as Technorati so that they are immediately published to the world at large.