The degree to which a piece of internet content has been or might be shared in a short amount of time. First coined by CollegeHumor co-founder Ricky Van Veen.
Research into influence and virality suggest that finding swayable audiences is far more important when it comes to spreading information than the apparent influence quotient of the person passing it on.
Lady Gaga's new single Telephone has been a massive success on YouTube due to its viralability. Its controversial content ensuring that it will be viewed widely and passed from friend-to-friend in social media networks such as Facebook, thus ensuring an ever increasing audience.
The level of which a service, site, post, or anything related to the internets is viral. Increased levels equate to increases of Web 2.0 manliness.
If DiDGU's going to be the 800lb gorilla that tears through the competitors like so many pieces of wet tissuepaper, we're gonna need more virality on the site.