Viral Marketing: Viral marketing, also called viral advertising and marketing buzz, is the term used to describe self-propagating marketing techniques. These tactics are used to help increase brand awareness or product sales, or achieve other common marketing goals. Common modes of transmission include email, blogging and word-of-mouth marketing channels, such as social media websites.

In a way, the twentieth century could be called the Age of Viral Marketing: due to the stable popularity of social media and content sharing websites, it is easier than ever for companies to produce viral content and respond to popular topics. As a result, the images and other content that are produced must be appealing, interesting, timely and, in many cases, relevant to popular culture. The best examples of viral marketing, therefore, often mimic internet memes, or popular pieces of content which spread rapidly from user to user. In some cases, companies have even managed to create unique internet memes, either by accident or design. Depending on the context, this can be either highly beneficial or even detrimental to the company's brand image; in some cases, viral marketing content has been adapted and successfully used against the company. For this reason, it is important to ensure that a company is producing quality content.