Because "viral" is a hip, new buzzword that makes commercials less obnoxious some how.
"viral" = "we don't explicitly tell you it's an ad, and over 50% of youtube users are too dumb to realise"
Viral is pretty cool. Nobuyuki Hiyama is my favorite voice actor ever.
This reply is a viral AIDS.
Megabyte kicks all kinds of ass. Remember that guitar dual with Bob? That was totally sweet.