Trump, of course, was the canny marketer, while Clinton’s team was the unengaging competitor. While most everyone covering the digital portion of the election has known this, the logical conclusion that follows can still feel startling.

“During the run-up to the election, the Trump and Clinton campaigns bid ruthlessly for the same online real estate in front of the same swing-state voters. But because Trump used provocative content to stoke social-media buzz, and he was better able to drive likes, comments, and shares than Clinton, his bids received a boost from Facebook’s click model, effectively winning him more media for less money,” García Martínez continues. “In essence, Clinton was paying Manhattan prices for the square footage on your smartphone’s screen, while Trump was paying Detroit prices. Facebook users in swing states who felt Trump had taken over their news feeds may not have been hallucinating.”

After the article was published, one of Trump’s campaign staffers, Brad Parscale, posted a link to it and tweeted a chest-pounding follow-up. “I bet we were 100x to 200x [Clinton],” he wrote. “We had CPMs [cost per thousand impressions] that were pennies in some cases. This is why @realDonaldTrump was a perfect candidate for Facebook.”

No one has the precise numbers for how much more engaging Trump’s ads were or how much less money he paid to reach people than Hillary Clinton. But it’s clear that Donald Trump—aided by bots and this advertising boost—far outstripped Clinton in overall engagement. Mark Zuckerberg pointed this out back in November of 2016.

For example, during two months in the run-up to the election that the data journalist Kate Stohr looked at overall interactions (likes, comments, shares), Trump had almost three times Clinton’s engagement, 36 million to 12 million. Of the two months in the dataset, Clinton’s total interactions only topped Trump’s on three days.

Trump was a socialgenic candidate with a team that maximized—or exploited—his potential to create engagement: As dozens of stories have attested over the last two years, Trump was the “clickbait candidate.” Clinton’s posts and advertisements, for whatever basket of reasons, did not generate the same volume of likes, clicks, and shares. And in today’s electioneering, that has severe consequences.

While this much has been known, García Martínez’s logical conclusion that this means there was an ad-pricing differential seems to have hit a nerve. That’s because FCC election regulations require that candidates be charged equal rates. “The rates, if any, charged all such candidates for the same office shall be uniform and shall not be rebated by any means, direct or indirect,” the regulation states.

The FCC promulgated this regulation to cover broadcasting, but on its face, it would seem to present questions not just for Facebook, but for any auction-based advertising platform such as Google’s, Twitter’s, and various ad networks.