Bank statements and invoices reviewed by the Journal show that Mr. Patch billed Marathon, and was paid thousands of dollars for promoting a variety of Marathon projects. One line item on Mr. Patch's spreadsheet of outstanding invoices noted $1,175 for placing an article, subject: "Amazon piece."
Mr. Patch said the documents referred to by the Journal were "unrecognizable" and said "I have been the target of an ongoing misinformation campaign." He did not address directly the question of whether he was paid by Marathon.
Marathon said it has "engaged Mr. Patch for editorial and research services in the past."
RealClearMedia Group executive editor Carl Cannon said the article was an unpaid guest op-ed. The editors who published the piece are no longer with RealClearPolicy and Mr. Zeiser, the current editor, said his predecessors "were unaware that the author was being paid by Amazon's business competitors."
Free and Fair Markets has tweeted more than 1,060 times and produced glossy videos, some of which it has circulated through thousands of dollars in paid advertising, according to Pathmatics, an independent company that tracks social-media ads. A review of the tweets shows that aside from four tweets about FoxConn Technology Group, which assembles Amazon's smart speakers, all of the tweets are about Amazon or an Amazon-related issue. The tweets have attacked Amazon on several fronts, including antitrust, worker rights, data privacy, soliciting subsidies from local governments for its second headquarters and its bid for the Pentagon cloud contract.
Marathon officials said the group will expand to address other companies' abuses. "The organization has started looking at FoxConn and is preparing to scrutinize other tech giants," Marathon's statement read. Taiwan-based FoxConn, a major supplier also to Apple Inc., got $4 billion in public support to locate some of its operations in Wisconsin.
More than two dozen tweets are particularly critical of Amazon's bid for the cloud-computing JEDI contract.
One tweet said, "As if $1.5 billion in state and local corporate welfare wasn't enough, @amazon wants $10 billion more from American taxpayers to host the @DeptofDefense most sensitive data," and then linked to a list of stories that recounted the complaints of a primary opponent for the contract, Oracle -- mainly that the technical specifications in the JEDI request for bids had been "rigged in favor of a single provider: Amazon." Oracle sued in an attempt to block the Pentagon from awarding the contract, but a federal judge ruled in July that the bid could proceed.
Amazon has previously said that Oracle's claims are "meritless and a desperate attempt to distort the facts"
None of the members listed by Free and Fair Markets on its website seemed to have an obvious issue with the cloud-computing contract or several other of the group's issues. When the Journal began inquiring with the members about their reasons for being listed -- some did not know their names were posted on the website -- the group took them down.
Marathon said, "The names of the groups listed on the site were removed at their request after we heard complaints about some receiving harassing phone calls" from journalists.
One listed member, Aubrey Stone, was founder and head of the California Black Chamber of Commerce. He died in September 2018. His name remained listed as member until at least June and wasn't removed until the Journal contacted the group.
Maria Gillette, a member of the largely inactive Carbondale Tea Party outside of Scranton, Pa., is listed as an advisory member of Free and Fair Markets. Ms. Gillette, known in her small community for appearing in national media in 1974 after seeing an unidentified flying object, said she thought the group was about free trade -- not Amazon.
The New England Convenience Store & Energy Marketers Association is listed as a member, and Jonathan Shaer, executive director, said the group is aligned with its stated principles but does not share the anti-Amazon animus. Mr. Shaer said his association "hasn't had any active involvement in any of the Initiative's activities."
Benyamin Lichtenstein, a business professor at the University of Massachusetts Boston, said he was contacted out of the blue by a Boston corporate public relations firm last year about signing his name to an op-ed opposed to Boston's bid for Amazon's second headquarters. The firm sent a draft of the op-ed that called on Boston politicians to "reject an Amazon headquarters for the sake of small businesses." The PR official wrote in an email to Mr. Lichtenstein, "If you are happy with the draft we can submit it as is," according to a copy of the email reviewed by the Journal. The article was pitched to Boston newspapers and was eventually published in DigBoston.com.
Chris Faraone, editor-in-chief of DigBoston, said Mr. Lichtenstein first submitted the article, but that DigBoston didn't publish it until receiving an email from the same public-relations representative who had initially contacted the professor.
"As for whether Lichtenstein wrote the piece himself, we assumed that was the case, but if it wasn't, we assure you that we're no more surprised to hear that than we are when politicians or celebrities use ghostwriters," Mr. Faraone said.
Mr. Lichtenstein said he agreed to sign his name to the article, to which he made some changes and checked citations, because he believes in advocating for small businesses.
Told he was listed online as a member of the group, Mr. Lichtenstein said, "Wow. I had no idea." He said the group had inflated his role.
In a statement, Marathon said, "All of the individuals and groups that we work with have full editorial control and input on any materials they put their names on. In fact, those who play a more formal role with the group sign agreements that clearly spell out the mission and vision of the group."
Mr. Singer provided the Journal a copy of Mr. Lichtenstein's signed agreement.
Service Employees International Union Local 721, which represents more than 95,000 workers in Southern California, was named as a member without permission, said Coral Itzcalli, communications director. "We have zero involvement with that organization," she said. After being contacted by the Journal, the union's attorney sent a cease-and-desist letter demanding the removal of the union from the list of members. A few days later, it was.
Asked for comment, Marathon emailed to the Journal a membership agreement that the agency said had been signed by Gilda Valdez, the chief of staff for the union local, dated July 23, 2018. The firm also provided a statement from Juan Carlos Mendez, president of Churches In Action, a Christian community group in South Gate, Calif., stating that he had asked Ms. Valdez to join the group and had "secured her signature of FFMI's consent form."
But Ms. Valdez said that the signature on the documents provided by Marathon was not hers.
"I did not sign on with this group," she said. "Their real motive for listing us as supporters remains unknown to us."
-- Sarah Nassauer, Esther Fung and Jay Greene contributed to this article.