Viral marketing is usually refer to a marketing techniques that use pre-existing social networks like forums or blogs to produce increases in brand awareness or to achieve product or service sales through self-replicating viral processes just like virus. This technique sometimes can be called word-of-mouth marketing which delivered by the network effects from the Internet. The reason that viral marketing is successful is because people voluntarily help passing a marketing message. Also, that many researches have demonstrated that a customer tells fewer people about a product or service he/she likes but spread to a lot more people than the products or services that he/she did not like. So, marketers like to use and take advantage of this natural human behavior in order to generate more buzz for their brands. Still, there are more specific strategies and guidelines for marketers to follow: “Gives away products or services, provides for effortless transfer to others, scales easily from small to very large, exploits common motivations and behaviors, utilizes existing communication networks, and takes advantage of others’ resources”. For example, marketers usually give away their new products for free as the samples in order to attract more customers to visit and further learn more about other product lines. To the real world, there are some remarkable examples of viral marketing campaigns of all time. One of the most famous video is from Nike, and it successfully attracts more than 23.5 million people to watch it. Click here to see the top ten viral marketing campaign of all time! However, some researches have thought that viral marketing is effective due to an aspect of emotional engagement which describes the information recipients have a strong emotional connection with the specific message. So, researchers have listed the six primary emotions with a strong influence on viral referral behavior which are “Surprise, joy, sadness, anger fear, and disgust”. It’s interested to see disgust can be a type of viral marketing.