Google Trends - The big catch

I love this new addition to Google Trends. Google Trends used to just show the level of searches on a specific term, but now you can look up site traffic trends, like on Alexa.

So here is the chart for Friendster, MySpace, & Facebook globally


But... Here's the catch. They're not letting you see data for Google's own sites. So this is what you get when you search for YouTube, Blogger & Google

"Your websites - youtube.com, blogger.com, google.com - do not have data to display.

Suggestions:

• Make sure all websites are spelled correctly.
• Try different websites.
• Try viewing data for all years and all regions."

If you click on the link to see more information it tells you:

"10. Are all websites included?

No. Not all websites are included in Trends for Websites. The following types of websites may not appear in the tool:

• Websites with low traffic volume below our threshold
• Websites that don't wish to be indexed by Google and have indicated their preference through a robots.txt exclusion file
• Websites that don't adhere to our Quality Guidelines
• Other websites for miscellaneous reasons"

Hmmm. Come on Google, give everyone a level playing field. What have you got to be scared of?

UPDATE - this is a good explanation:

"A better explanation, provided by one of our commenters. is probably that Google simply isn’t able to use its own tools for estimating traffic - since by definition all the data is being gathered by Google for the product is from Google users (their toolbar, for example), the data for Google’s sites would be skewed to 100% of all Internet users. It points out an inherent flaw in the product, and I’m not sure Google can easily solve it."