Viral:

A video, photo, or meme that quickly gains popularity through social media such as Facebook, Twitter, YouTube, or Instagram. The viral content is usually comedic in nature, but can also be emotional, shocking, or a music video.

Viral can also refer to “Viral Marketing,” which is a business strategy that uses social media to promote a product or service. Similar to a viral video or meme, the advertising is spread through users on social media and mobile networks.