Facebooked by the Trump campaign according to an internal Facebook whitepaper, published days after the election. And that's excluding the alleged "help" of Russia.
"Both campaigns spent heavily on Facebook between June and November of 2016," the whitepaper's author wrote, citing internal revenue figures of $44 million spent by the Trump campaign vs $28 million for Clinton during the same period. "But Trump's FB campaigns were more complex than Clinton's and better leveraged Facebook's ability to optimize for outcomes."
The paper, first obtained by Bloomberg and "describes in granular detail the difference between Trump's campaign, which was focused on finding new donors, and Clinton's campaign, which concentrated on ensuring Clinton had broad appeal."