Viral marketing is defined as marketing techniques that exploit social networks to exponentially increase brand awareness through viral processes similar to the spread of an epidemic. Traditional marketing focuses on selling products and maximizing profits in the short term, while modern marketing prioritizes customer satisfaction and building long term customer relationships by understanding customer needs. Techniques of viral marketing include buzz marketing, where consumer interactions amplify marketing messages on social media, and word-of-mouth marketing, where companies generate personal recommendations and referrals. Examples of successful viral marketing campaigns are then presented.