Viral marketing is a strategy that uses social networks to generate word-of-mouth buzz about a product or service. By harnessing the power of existing networks, businesses can reach a large number of potential customers at a relatively low cost. The key to successful viral marketing is creating content that is interesting and shareable. This can be achieved by creating compelling video content, developing engaging games, or offering discounts and giveaways. While there is no guarantee that a viral marketing campaign will be successful, it can be an effective way to reach a large audience with minimal effort.