[3][4] In 2016 Amazon banned the practice of reviewing complimentary products, researchers have shown that the process still continued as of 2021, but without any disclosures.
Most recently (June 2021), the Competition and Markets Authority (CMA) in the United Kingdom has launched an investigation into whether Amazon and Google are doing enough to prevent fake reviews from being published on their sites.
[10] In 2010, British historian Orlando Figes posted reviews on Amazon praising his own work and criticizing that of his rivals.
[11] In August 2012, The New York Times revealed that John Locke had paid an online service to write reviews of his books, in order to artificially boost sales.
[12] In 2022, researchers from UCLA documented that millions of Amazon sellers purchase fake 5-star reviews through private Facebook groups.
[15] Examples of spoof reviews include: British spoofers have targeted several build to order novelty products made by Media Storehouse from two million licensed photo library images, including a canvas print of minor celebrity Paul Ross, and a jigsaw puzzle of Nick Humby, a former finance director of Manchester United.