To claim web 2.0 can be considered SEO on steroids would first require an exclamation as to what exactly is web 2.0. Over the recent past there's been a silent revolution taking place regarding the fundamental design and functionality of many popular web sites.

Formally the general structures of most online sites allow the visitor little or no ability to actually interact with the site itself much beyond leaving a name, email address, or some such other form of id. They were limited to the role of mere spectators with little or no say regarding site content, layout, or format.