People have been trying to harnass the power of the successful viral marketing campaign by encouraging people to spread the message themselves. This technique was served to great effect for environmental causes with the (anti) Chevy Tahoe campaign, which generated a lot of buzz to the effect that environmentalists had turned Chevy’s marketing on itself. However, it’s an open question as to who took advantage of whom.
NetSquared: Remixing the Web for Social Change