It was widely reported last week that Facebook topped the 350 million global user mark, and the social-networking site topped another milestone, as Inside Facebook reported that according to Facebook’s advertiser tools, the site now boasts more than 100 million active monthly users in the United States.

According to Inside Facebook, this means that nearly one-third of the total population of the United States logs onto Facebook each month.

Inside Facebook added that the second-largest Facebook country is the United Kingdom, with 23.2 million monthly active users, and Turkey is No. 3 with 16.5 million.