Viral Marketing is where someone creates content so interesting that people share it widely for free (often on Social Media). It is called Viral Marketing, as the content spreads like a virus – rapidly and from person to person.
These types of ads often don’t seem like advertising at all, and often don’t even start out as such. They can be images, videos or even just ideas.
A notable example would be the ice bucket challenge which raised awareness (and money) for the disease ALS.Glossary Index