Technically, the Enquirer paid McDougal $150,000 for the story of her affair with Trump, much as tabloids frequently do for stories. The Enquirer just didn't publish it. So we're all clear on dates, the Enquirer and McDougal reached their agreement in early August, just after the Republican and Democratic conventions. Indeed, it was likely during the Trump-Khan War which took up much of the first half of August.
As The Wall Street Journal describes it, McDougal didn't think she was taking hush money. She thought the Enquirer was going to run her story. But they didn't.
This isn't the first of the Trump-Pecker alliance (I know, I know). During the spring Pecker ran interference for Trump running damaging stories against Trump's enemies of the moment. It was the Enquirer that ran the story suggesting that Ted Cruz's dad was tied to the Kennedy assassination. In March, the Enquirer ran a story with unsubstantiated claims of Cruz affairs. A source The New York Daily News called an "industry insider" said “Trump is a big friend of Pecker. So no John Edwards-type investigations.”