Unofficial estimates indicate that Google+ experienced its best traffic month ever in December 2011. The site garnered more than 49 million visitors in the US, according to web analytics firm Experian Hitwise in a recent Tweet.

The Tweet and accompanying chart indicate that not only was December the best month ever for the budding social network but traffic was up 55 percent from the previous month.

Experian Hitwise isn't the only one singing praise for Google+. Last week we reported that co-founder and self-proclaimed Google+ unofficial statistician Paul Allen believed that the company had topped 62 million users at a pace of around 625,000 new members each day. ranked as the top overall web destination for US surfers in 2011 while their social network finished in 8th place in the top 10 US social networks and blogs category with an average of 8.2 million unique visitors per month. Of course these stats are highly skewed as Google+ didn't launch until late June 2011.

There's no doubt that the holiday season and the number of new Android device activations helped funnel traffic to the social network and it remains to be seen if that traffic will slowly die off as we look back at December in the rear-view mirror. Additionally, Google has been integrating + with several of their other properties including Piscasa Web Albums, Gmail, Reader and search to cross-promote their product lines.

At its current rate, Google+ could reach 100 million users before the end of February and double that by August.