14th Week--Newest tactic to PR

Word of Mouth (aka: buzz marketing)--that's the newest and most popular way to spread the word these days. Some say that this type of communication is credible but to an extent. Flaquery and fakeness (ie: fake blogs) can possibly come into play here. At the same time buzz marketing believes to get across to individuals and customers better than more formal approaches. This is all based on the factor that the "buzzer" is giving credible information which is not always the case.
Ethical concern and considerations must always be present for Word of Mouth to be successful. Here are some examples:

-Youtube.com (more people visited the site and would tell friends/family to visit to watch specific video.)
-Myspace.com (Satisfaction from those few customers initially told those to visit site and to create their own.)
-Gmail (No money was spent; accounts were given to "power users" only and others aspired for that title and as a result Gmail's "buzz" soared successfully.)