Big companies frequently hire ad agencies to do grassroots marketing. Employees pose as members of online communities and promote products with seemingly spontanious testimonials. If done correctly it can be a really powerful tool but it can also backfire if it isn’t genuine and/or well-done. Here’s an entertaining example with Joel Johnson at the popular blog Boing Boing Gadgets calling out a character named M. Goode for pontificating the wonders of Motorola’s new Krave phone:

Motorola, could you please tell your viral marketer to get out of our comments?