Microsoft would fall to fourth place from its prior number two position.
Due to a change in its measurement system, analytic firm ComScore has increased Facebook's traffic figures, but Google still remains the dominant website in terms of the number of visitors on both desktop and mobile.
ComScore, a company that tracks website visitors and other similar data, revealed its new digital audience measurement and media planning tool in the form of the "Media Metrix Multi-Platform."
The platform is currently in a beta stage in the U.S., with its technology tracking metrics including audience size and demographics on desktop browsers and mobile devices. The new system also accounts for users utilizing multiple devices to access the sites.
"With smartphones and tablets accounting for a rapidly expanding share of digital media consumption, comScore recognized the need to evolve our industry-leading audience measurement product to better represent this new paradigm," Jeff Hackett, executive vice president of ComScore, explained. "By developing proprietary methods to account for multi-platform audience overlap, we have designed a truly unique and innovative solution."
For Facebook in particular, the Media Metrix Multi-Platform makes it the third-most-visited site on the web during September via 179,411,000 visitors. When judging by desktop traffic, it would drop to fourth place.
Google remains at the top spot by using either ComScore's new measurement strategy or its old platform. It was the only site to surpass 100 million unique visitors on both desktop and mobile.
ComScore said the platform will remain in beta over the next few months as the product is put through a comprehensive data review and validation with its clients. It stressed that publicly reported data should not be interpreted as official ComScore data/rankings.