DISQUS

I agree, those two wouldn't be geekspots, but it's important to note that this is a terribly difficult question to frame and answer properly

For kicks, here's some statistics from the website of a regional bank with about 90 locations. These are the percent of all referrals by month for February-October.

Just an anecdote...

Google Yahoo MSN
1.4% 1.1% 1.1%
2.7% 2.3% 2.1%
2.8% 2.2% 2.0%
3.0% 2.1% 2.0%
3.1% 2.0% 2.0%
3.2% 2.2% 1.9%
3.3% 2.3% 2.0%
2.7% 1.7% 1.3%
3.1% 2.1% 1.8%

For a conflicting anecdote, my blog gets nearly 100% of its searches from Google: iwtiwil.blogspot.com

Most of my search referrals come from Wii Tennis terms.

You need to make sure that the corpus of site you are examining isn't demographically skewed. If you look at tech sites (or even smart people sites :) ) then you will find a lot of people using Google (and Firefox).