CGM “encompasses the millions of consumer-generated comments, opinions and personal experiences posted in publicly available online sources on a wide range of issues, topics, products and brands” and originates from:
CGM * Blogs
* Message boards and forums
* Public discussions (Usenet newsgroups)
* Discussions and forums on large email portals (Yahoo!, AOL, MSN)
* Online opinion/review sites and services
* Online feedback/complaint sites (www.hellopeter.com)
Intelliseek have published a concise report on Consumer-Generated Media: What it is, why it’s important and how it’s growing.
I like their “speakers” and “seekers” concept.

TomorrowToday Global