Viral marketing is a form of advertising and marketing where distribution relies upon persons not associated with the company spreading news of its products and services. An example of this can include viral marketing video posted to sites like YouTube which are then shared within personal networks. Viral marketing campaigns have become extremely successful especially given their sometimes very low production costs. A great example is a viral video of cell phones popping an uncooked popcorn kernel that garnered millions of hits on YouTube - as it turns out the video was produced by a bluetooth headphone manufacturer tapping into fears of cell phone radiation.
The key to successful internet viral marketing is a topic that is shocking or fascinating, can be easily shared with friends and networks through tools such as YouTube, Facebook, MySpace and other such sites, and does not overtly market the companies products and services.