Viral marketing
Also known as: viral marketing
Freely translated, viral marketing is a form of marketing that spreads like a virus (viral). Basically, it is word-of-mouth advertising(buzz) which can reach a large number of people quickly and inexpensively (if done well) due to today's communication capabilities and speeds.
Think of distribution as sharing via social media, among other things. When content is created with the goal of spreading it across the Internet, we also refer to it as linkbait.