Viral marketing, viral advertising, or marketing buzz are buzzwords referring to marketing techniques that use pre-existing social networking services and other technologies to try to produce increases in brand awareness or to achieve other marketing objectives (such as product sales) through self-replicating viral processes, analogous to the spread of viruses or computer viruses

The content created for viral campaigns is often classified as an Internet meme.

Content propelled by viral marketing can be delivered by word of mouth or enhanced by the network effects of the Internet and mobile networks.