Google's market share increase came just as Microsoft announced that it's teaming up with Facebook to make search more "social."
"When you search for something on Bing or in web results on Facebook (powered by Bing), you'll be able to see your friends' faces next to web pages they've liked. So, you can lean on friends to figure out the best websites for your search," Facebook official Bret Taylor wrote in a blog post.
Bing, of course, already powers Yahoo searches, making it the most serious competitor to Google in terms of providing back-end search technology.
Bing has enjoyed a fast rise, coming online only in June 2009, replacing the previous Microsoft service known as "Live Search."
Despite Bing's quick start, Google's market share has remained pretty steady. Google held 65% of the market in May 2009, whereas Yahoo held 20% and Microsoft held 8%, according to comScore. Bing's impact has therefore been more pronounced on Yahoo's market share than on Google's.
ComScore is not the only firm analyzing search share. According to Hitwise, Google did even better in September than comScore indicates. Hitwise numbers show Google increasing from 71.59% in August to 72.15% in September.