Around six million Facebook users in the US recently unplugged their lives from the dominant social network.
According to data garnered by Inside Facebook Gold, the Mark Zuckerberg-run company saw its base significantly slip Stateside from 155.2 million users at the beginning of May to 149.4 million by the end of last month.
Similarly, Facebook's users' headcount in Canada was down 1.52 million to 16.6 million, while the UK, Norway and Russia each saw losses of more than 100,000 users by the end of May.
The report noted that each of those countries had been early adopters of Facebook.
Worldwide the firm picked up an extra 11.8 million users in May, but that figure was down from the 13.9 million people who signed up to the closed-off network in April this year.
Significantly, growth has slowed over the past two months.
"In contrast, it grew by at least 20 million new users over the typical month in the past 12," said the report.
It's understood that Facebook, which is expected to take the company public in 2012, is close to a 700 million userbase. However, there appears to be a trend developing in signups.
Inside Facebook Gold said that once the social network hits 50 per cent of a given country's population, growth seems to effectively stall.
Up to now, the company has offset those halts in its more mature markets by gaining from take-up in countries such as Mexico, Brazil, India and Indonesia.
"But how much further can it go if it is to reach its goal of 1 billion monthly active users?" asked Inside Facebook Gold.
A foothold in China is the obvious growth fix with its 420 million netizens. The only trouble there being that the Great Firewall currently denies Facebook access. ®