Yesterday, MG Siegler wrote a blog post at TechCrunch pointing out a mysterious Google Trends drop for major social sites like Facebook, YouTube, Twitter, Flickr, and Foursquare somewhere in the January of 2010. The drop is only visible with searches for the domain name (not word), for example Google trends for “facebook.com”, not “facebook”. Basically, something a user should write in the address bar instead of the Google search box.

We still don’t have exact theory on what happened, but reading through comments it appears we have a fine idea on what might have caused this “coincidental” decrees in search volume for these major brands.

Joey Primiani has offered an explanation: “It is the inclusion of the providing the direct link inside Google Suggest.”

Following up to that comment, Dain Binder of the dainsmoviereviews.com adds:

Joey, I just did some tests on this and I think you are correct. When searching for “facebook.com” and going to the results it registers a search. When searching “facebook.com” and clicking on the suggestion direct link it does not.

I would say Google Trends is more accurate now; eliminating people that use it as a “browser”.

(Verified using Chrome with SideWiki with full search and browsing history saved by Google.)

Google’s engineer Matt Cutts joined the thread with:

I don’t have any first-hand knowledge and haven’t asked anyone else at Google about this, but I’d lean toward this sort of explanation.

Basically what this means is, Google is including the direct links for domain quarries to “fix” the problem of typical users who actually wanna “feel lucky” instead of search for all websites that contain the URL they entered in the search box.