The September 4 issue of Brandweek magazine contained a small note on how Gary Spangler, who is responsible for word-of-mouth campaigns on behalf of DuPont, rescued the term "word-of-mouth" on Wikipedia. Spangler heard the free online encyclopedia was considering eliminating the term in favor of "viral marketing". He communicated this to the Word of Mouth Marketing Association, among others, to pressure Wikipedia into not making that change.
Spangler defines viral marketing as a subset of word-of-mouth, along with referral marketing and brand blogging, among others. Thanks to him, word of mouth has saved word-of-mouth. Spangler admitted that Wikipedia is the real winner:
If anything, this demonstrated how Wikipedia works. it highlighted how you can get involved to present your viewpoint.
In my view, all these different types of marketing, sets and subsets alike, are part of the larger conversation taking place between producers and consumers.