It is used to say that something has spread rapidly, and is popular.
I suppose the idea is that it is spreading like a virus - widely and rapidly.
No viral means becoming very popular by circulating quickly from person to person, especially through the Internet.
If something such as a video goes viral online, it is spreading out all over the internet. Very popular, lots of views, etc.
Viral means becoming extremely popular in a very short amount of time. Often for something to be considered viral it needs to make its way into everyday non-internet life. Mark Moloney is considered by many to be imminently viral as a result of his many video antics recorded during a recent visit to India which have recently been posted on YouTube.
Viral marketing is also called viral advertising. It is a means of using mouth-to-mouth communications like social networks to spread a company's or brand's message through the Internet or email.
For something to become "viral" it must contain content delivered through social interaction that excites and engages others to repeat.
cannot be transmitted
A Viral Video is a video which gains viewings and notoriety rapidly as people share it and watch it repeatedly. There are many examples of viral videos now that youtube has come about on the internet as it allows people to share their videos easy and quickly.
You have a viral infection.
"Going viral" can mean many things. Mostly, it usually means going public. As in, almost everyone.
it means it spreds among people quicly, like a virus
viral means pertaining to or caused by a virus It means spreading quickly over a short amount of time
When some spreads quickly