A study of HubSpot customers shows even more Google dominance, as you can see in the chart below.
Search Referrals for HubSpot Customers
June -August 2009
This data came from a sample of 40 HubSpot customers across industries for the 3-month time period from 6/1/09 to 8/31/09.
Google had over 85% market share versus Yahoo, Bing, AOL and Ask.com for this customer group. The results were fairly consistent for each industry with Google market share ranging from 82% for construction firms to 87% for software companies.
While Google's astronomical market share for these customers is much higher than what comScore reports, it's consistent with what we've been seeing anecdotally over the past year with other HubSpot customers.
More research would be needed to definitively know why Google holds such a strong position as the referrer to these customers relative to the other search engines.
It could be the sample set, a significant difference in characteristics of HubSpot customers versus the sites measured by comScore, or a difference in the way the data was analyzed by HubSpot and comScore.