Citing census data, an equity research analyst claims Facebook is once again inflating one of its key metrics, this time grossly over-reporting its ability to sell ads and effectively inventing millions more young Americans than actually exist.
Facebook told advertisers that the platform can potentially "reach" 41 million young adults between 18 and 24 in the US. Brian Wieser of Pivotal Research Group countered by pointing out that 2016 census data shows there were only 31 million people in that age range in the US. Similarly, Facebook claims it can reach 60 million people in the US between 25 and 34 years old. The census reports 45 million in that age group.
Alongside his findings, Wieser called for greater transparency in "reach" calculations and called for Facebook to double check its numbers against audits from third-party partners. Any statistician could spot the problem in reach calculation from 100km away. From The Wall Street Journal:
Facebook's age data is based on what users report when they register, which may be inaccurate. Users also might open multiple accounts, which could also contribute to the mismatch between the social network's numbers and official government statistics. And the Facebook reach data, which is based on a sample of users and extrapolated out, includes nonresidents or visitors that aren't tallied in the census.
The company, however, reportedly already has 20 different third-party audit partners and, in its explanation for the massive discrepancy, rejected the notion it'd done anything wrong.
"[Reach estimates] are based on a number of factors, including Facebook user behaviours, user demographics, location data from devices, and other factors," a Facebook spokesperson told the Journal. "They are not designed to match population or census estimates. We are always working to improve our estimates."
Facebook doesn't have to admit wrongdoing because the murky calculus of "reach" scores is, by their own admission, designed to report big numbers. Simply put, "reach" is an arbitrarily defined metric created to sell ads. Its purpose is generating business from advertisers. Facebook's 10 million theoretical millennials aren't evidence that the system is broken, but proof that its working exactly as intended.