Nearly 9 percent of all Facebook profiles on the site are fake, a figure that has risen since Facebook's troubled public debut in May, when it estimated "false" profiles accounted for 5 percent to 6 percent of its users, the New York Post reported Friday.
"These estimates are based on an internal review of a limited sample of accounts, and we apply significant judgment in making this determination, such as identifying names that appear to be fake or other behavior that appears inauthentic," the company said in a recent regulatory filing.
Advertisers and investors questioning Facebook's effectiveness in reaching consumers find fakes a major concern, an analyst said, especially since Facebook has been under scrutiny for slowing ad sales revenue.
On Aug. 16, Facebook insiders will be allowed to start selling their stock, and up to 2 billion more shares will flood the market.
"The question for many investors is why not wait," Ken Sena, an analyst with Evercore Partners, said.