How Many Users Does Facebook Have? The Company Struggles to Figure It Out

Facebook is struggling to detect and deal with users’ creating multiple accounts on its flagship platform, according to internal documents that raise new questions about how the social-media giant measures its audience. An internal Facebook presentation in spring 2021 called the phenomenon of single users with multiple accounts “very prevalent” among new accounts. The finding came after an examination of roughly 5,000 recent sign-ups on the service indicated that at least 32 percent and as many as 56 percent were opened by existing users. The company’s system for detecting such accounts also tends to undercount them, according to the presentation. A separate memo from May 2021 said that the number of US Facebook users who are in their 20s and active at least once a month often exceeds the total population of Americans their age. “This brings out an elephant in the room: SUMA,” the memo’s author wrote, using an internal abbreviation for “Single User Multiple Accounts.” The author added that the issue could render Facebook’s ratio of users active each day “less trustable.” At issue is the reliability of the information that helps inform some big advertisers’ spending decisions. While Facebook says it doesn’t bill advertisers based on its estimates of an ad’s target audience, some advertisers look at those estimates when planning where to allocate their budgets—especially big brands that have turned to Facebook to reach large audiences as broadcast and cable television viewership have declined.