An author writes something, and then someone else reads it. There are some costs involved — who should pay them? The writer or the reader? Obviously, the one who gains from the “transaction”: if we are talking about useful or interesting information, then the reader; if we are talking about some form of advertising, then the writer.
The same principle should be true in academic publishing as well. It used to be that the readers paid to read academic journals. Publisher abuses of the system, together with the new possibilities opened by the Internet, caused academics to talk about open access journals that do not charge readers. The main associated costs are those of producing the research and these are anyway paid by government grants as well as professor salaries. Unfortunately, it seems that the tide is turning towards “open access” journals like PloS ONE in which the authors pay for their results to be published.
By definition, papers published in such journals are equivalent to advertising: you pay for others to notice you. The dynamics of such journals cannot maintain quality: they have strong incentives to increase quantity and have weak (or no) incentives to increase quality. Indeed, PLoS ONE does not hide it:
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).
From my point of view, this reduction in the role of referees makes the journal superflous: information that is unfiltered for quality, becomes useless since it is impossible to find the good stuff there — you might as well just put your paper on the arXiv (see also my post on the attention economy). I personally also don’t quite trust the referees for correctness, not in other journals and certainly not here — correctness is established after the “community” has chewed on the paper for a while (which will only happen if it is interesting). I find it hard to believe that any favorable reputation will be attached in the long run to publication in such places — they’ll mostly be a sink for readerless publications.
Let me just be clear: in no way am I defending the expensive “closed access” journals. It is not so difficult to just put your work openly on the web. If you also need a journal publication for your own promotion/grants, then do what you need to. But don’t forget: the “science” part is the making it available; the “journal” part is a bureaucratic hurdle.