There have always been publishers that take advantage of uninformed authors or readers by selling them low-quality services or products at inflated prices. However, the Gold open access (OA) model, with its high processing fees, lends itself to a particular type of abuse called predatory publishing.
There is no clear-cut definition of exactly what predatory publishing is. One definition, published in Nature, states that predatory publishers are "entities that prioritize self-interest at the expense of scholarship and are characterized by false or misleading information, deviation from best editorial and publication practices, a lack of transparency, and/or the use of aggressive and indiscriminate solicitation practices.” In practice, predatory publishers all share some common characteristics:
It is important to note that while most predatory journals are gold OA, most gold OA journals are NOT predatory and some very prestigious journals, like PLOS One are gold OA.
Overworked researchers who are now being asked to jump through yet another bureaucratic hoop by making their work publicly accessible are easy prey for unscrupulous publishers who appear to offer an easy solution. However, they do not provide any real peer review, editorial review, or any other type of quality control. Because of this lack of quality, they have become havens for questionable or even outright fraudulent research. This corrupts the research enterprise in several ways.
This does not mean that predatory publishers do not accept and publish high-quality research papers; they accept anything for publication regardless of quality. However, by publishing your high-quality research in one of these low-quality journals you are not likely to ever be cited and your research will remain largely unrecognized; essentially, you are throwing away your money and your credibility.