Web 2.0 is a term to express the sea-change that has occurred online in the past few years. Formerly, static content was common and websites were brochure-like. The advent of easily created and shared dynamic content means that the internet has shifted to a more conversational format. Web 2.0 can refer to everything from blogs to social networks -- but at its heart is the notion that individuals can self-publish. Interaction is also now common and easy between brands and consumers.

Recommendations about a business, product, or services that spread from person to person. Depending on the perceived credibility of the individual making the recommendations (individuals in our social networks tend to be very credible to us;) word-of-mouth marketing can be incredibly powerful.