The fact that people who spend lots of time watching videos on Google Inc.'s (Nasdaq:GOOG) YouTube site spend less time doing other things has been proven with the scientific precision of modern polling.

Harris Interactive found that 32 percent of frequent YouTube users say they are watching less television and 36 percent spent less time on other Web sites. Not surprisingly, 19 percent of frequent YouTube users said they spent less time working or doing homework. Yeah, I bet 100 percent of them lie to people who ask them questions for surveys while they are watching goofy video clips.

To make matters worse for the suits at Walt Disney Co.'s (NYSE:DIS) ABC, General Electric Co.'s (NYSE:GE) NBC, CBS Corp. (NYSE:CBS). and News Corp.'s (NYSE:NWS) Fox, the people who are big YouTube watchers are young males between the ages of 18 to 24, who television executives are finding increasingly difficult to attract. This fact certainly hasn't escaped the networks that are rumored to be in the process of negotiating deals with Google.

The poll also underscores the fickleness of the Internet. Almost three-quarters of the people who responded said they would visit the site less frequently if short video advertisements are shown before the clips. Take this with a grain of salt though. I would imagine that if the videos aren't just repurposed television commercials, viewers would put up with them provided they are engaging.

Even though new NBC head Jeffrey Zucker recently berated the company for not doing enough to protect copyrighted material and Viacom Inc. (NYSE:VIA) ordered YouTube to remove clips off its shows, the television networks are going to have to find some way to live with YouTube because the viewers that they are interested in attracting are already there.