"GM claims that its Fastlane blog generated $240,000 worth of free publicity for the company by having the blog featured by the press.
This isn’t blog coverage, which GM estimated as being worth an additional $37,000 to the company in the first year the blog was published."
(Of course, free isn’t exactly accurate. There are costs associated with setting up and maintaining the blog platform, paying bloggers, etc. Granted, these are nominal by comparison.)