Web Surfers Love the Tiger Woods Ad. Especially When It’s Not the Tiger Woods Ad.

No surprise that Nike’s (NKE) creeptastic Tiger Woods ad, featuring the disembodied voice of the golfer’s dead father, is a hit on the Web. Or at least, “well-viewed”; I’m not sure “hit” is the right term for the freak-show/marketing message.

More interesting is that the spinoffs, parodies, replies, etc., the ad has generated are now more popular than the original on Google’s (GOOG) YouTube and other sites.

So says Web video tracker Visible Measures, which estimates that more than half the seven million views the ad generated in the last week came from “derivative” sources.

The most popular “derivative,” according to Visible Measures: This one, which mashes up the also super-creepy “David After Dentist” audio with the original. This is where you shrug and say something like “takes all kinds.” Blech.