Those were by far the dominant findings in our first-ever Web Hosting Study, completed in October.
Those numbers swamped the use of Web servers hosted on departmental servers outside the data center (22.0%), hosted externally using dedicated server owned by the host (20.8%), and those hosted externally using company-owned servers in colocation facilities (13.0%).
The last number was the most surprising to me. Frankly, I expected colo-based Web hosting to be more popular.
The complete study, which digs more deeply into the topic, is available from BZ Research.