If you picked any Facebook user at random, there is nearly a 1 in 10 chance that the user you picked isn’t real. Maybe it’s a duplicate, maybe it’s a spam account – but either way, it’s a fake Facebook user.

How do we know this? From Facebook themselves, actually.

In their recent 10-Q filing with the SEC, Facebook released some hard figures on how many of their users they believe to be disingenuous. Here’s what Facebook had to say when describing “limitations of key metrics”:

For example, there may be individuals who maintain one or more Facebook accounts in violation of our terms of service, despite our efforts to detect and suppress such behavior. We estimate that “duplicate” accounts (an account that a user maintains in addition to his or her principal account) may have represented approximately 4.8% of our worldwide MAUs as of June 30, 2012.

We also seek to identify “false” accounts, which we divide into two categories: (1) user-misclassified accounts, where users have created personal profiles for a business, organization, or non-human entity such as a pet (such entities are permitted on Facebook using a Page rather than a personal profile under our terms of service); and (2) undesirable accounts, which represent user profiles that we determine are intended to be used for purposes that violate our terms of service, such as spamming. As of June 30, 2012, we estimate user-misclassified accounts may have represented approximately 2.4% of our worldwide MAUs and undesirable accounts may have represented approximately 1.5% of our worldwide MAUs.

Translation: 8.7% of accounts are either duplicates or “false.” Since Facebook just reported 955 million MAUs, that means they estimate their number of fake accounts to be…

83,085,000.

Don’t get me wrong, that’s a lot of fake users. Take the entire populations of New York City and Mumbai and multiply it by four and you’ve got the amount of fake Facebook users out there. But in terms of proportion – it really could be worse.

Take Twitter for instance. Recent reports put them over the 500 million account threshold. But according to Twitter themselves, it’s unlikely that they have any more than 160 million active users. That’s a whole bunch of inactive accounts.

But it just makes you wonder (especially as a page owner) whether 8.7% of your likes are from fake accounts? How about comments on your posts – are they spam accounts? And what about those ad clicks?

[via Geekosystem]