Compete: Facebook’s US Traffic Grew to 132 Million Monthly Uniques in December, 2009

Compete, the first of the big web measurement firms to publish their monthly traffic analysis every month, has released December results for Facebook. The data shows the service reaching 132 million unique visitors, the  highest number yet and up from 128 million in November.

This roughly matches with the growth Facebook saw over the course of last year. However, comScore and Quantcast show the service with around 100 million monthly unique visitors for November, while Compete showed a far higher number for that month (as it has before). One reason for this might be that Compete is counting people who use Facebook Connect on other sites every month, but do not go to itself, as we’ve previously noted. It’s not clear how large this group of people actually is.

Another data point: Facebook’s advertiser tool showed the service had nearly 103 million monthly active users in the US at the end of December, growth of around 4 million people from November. The advertiser tool is usually a month late in reporting data. So, when the other web measurement firms release their December data, we expect to see numbers somewhere above 100 million but well below 132 million.

Other potential data points on Facebook’s December traffic: Google Trends shows a monthly increase in US and worldwide searches for “facebook;”  Hitwise reported especially big spurts around Christmas and New Year’s.