<p>From among the 10 years' worth of footage uploaded to YouTube every day, a lucky video will occasionally rise up from the masses, skyrocketing to fame and earning the title of "viral video." This modern phenomenon rumor-spreading for the Internet age has come to play a central role in shaping the collective consciousness. </p><p> But since the birth of YouTube in 2005, which viral videos have spread faster and farther than all others? Visible Measures, a Boston-based company that analyzes online video performance, has crunched the numbers to find out. Defining a video's virulence as the impromptu speed with which it and the videos responding to it collectively rack up 100 million views and leaving out commercially produced music videos (as their release is often hotly anticipated) here is a countdown of the 10 most virulent viral videos ever. </p>
{youtube HttF5HVYtlQ} </p> <p> The original video, posted in August 2006, and related clips collectively garnered 100 million views over the course of 1 year and 3 months.
{youtube XQcVllWpwGs} </p> <p>This video, posted July 1, 2009, had a total reach of 100 million views over the course of 416 days.
{youtube _OBlgSz8sSM} </p> <p>Posted in May 2007, this video campaign accumulated 100 million hits in 402 days.
{youtube txqiwrbYGrs} </p> <p>After being posted in January 2009, this video of a loopy kid accumulated 100 million hits in just under a year.
{youtube ZN5PoW7_kdA} </p> <p> This comedy clip, and excerpts and responses to it, altogether racked up 100 million views in 167 days.
{youtube 1uwOL4rB-go} </p> <p>Footage of this comedy routine was watched 100 million times in 165 days.
{youtube TiFSSpYdPuc} </p> <p>This video game trailer and related clips quickly spread across the web in May 2009, racking up 100 million hits in 77 days. (Note: Justin Bieber and Miley Cyrus would rank ahead of this trailer if commercially-produced music videos were included; their videos for "Baby" and "Party in the USA" reached the 100 million views mark in 56 and 57 days, respectively.)
{youtube kfVsfOSbJY0} </p> <p> This 2011 video and related footage got 100 million views in 45 days. (Note: Lady Gaga's "Bad Romance" video would be No. 3 if commercially-produced music videos were included in the list; Gaga got to 100 million views in 18 days.)
{youtube RxPZh4AnWyk} </p> <p> This clip from the TV show "Britain's Got Talent" was watched 100 million times in nine days.
{youtube Y4MnpzG5Sqc} </p> <p> This famous video, posted March 5, and the hundreds of excerpts and responses uploaded all across the web, set a record by accumulating 100 million views in just six days.
