With all the attention directed at web video in general and YouTube in particular during the past eight months, I was genuinely surprised when I saw a blog post from web measurement gurus Compete.com this week, entitled “Top 20 Websites: Where DO we spend our time online”.

To be honest, I expected to read that viewers were glued to YouTube for large chunks of their day, and that the time they spend watching Mentos explosions and the like was surpassing all alternative pursuits.

The surprise? YouTube is #12 on the list, well behind MySpace, Yahoo, eBay, and 8 others.  0.6% of our collective time is spent on YouTube, while an astounding 11.9% of web viewers’ time is spent on MySpace.

Yes, web video is catching on, big-time.  But the new stats remind us that the time and attention of web viewers is limited.  And once the novelty has faded a bit, more and more viewer time will be spent on website-embedded video that not just engaging but truly useful.