PLoS ONE is a strange journal. Until recently, it was the largest journal in the world, publishing as many as 30,000 papers a year. It’s definitely the low end among the Public Library of Science (PLoS) stable of journals, but opinions of its quality vary over a wide spectrum. PLoS ONE‘s mission is explicitly different from most journals, as they say impact (i.e. significance) is not a consideration:
Often a journal’s decision not to publish a paper reflects an editor’s opinion about what is likely to have substantial impact in a given field. These subjective judgments can delay the publication of work that later proves to be of major significance. PLOS ONE will rigorously peer-review your submissions and publish all papers that are judged to be technically sound. Judgments about the importance of any particular paper are then made after publication by the readership, who are the most qualified to determine what is of interest to them.