Jon Christian, writing for The Outline:
People involved with the payoffs are extremely reluctant to discuss them, but four contributing writers to prominent publications including Mashable, Inc, Business Insider, and Entrepreneur told me they have personally accepted payments in exchange for weaving promotional references to brands into their work on those sites.
And:
An unpaid contributor to the Huffington Post, also speaking on condition of anonymity because, in his words, “I would be pretty fucked if my name got out there,” said that he has included sponsored references to brands in his articles for years, in articles on the Huffington Post and other sites, on behalf of six separate agencies. Some agencies pay him directly, he said, in amounts that can be as small as $50 or $175, but others pay him through an employee’s personal PayPal account in order to obfuscate the source of the funds.