I have noticed that scholarly journals are increasingly making their articles available for free if the authors pay certain fees. The fees can be quite expensive (several thousand dollars). I was told that making the article available online for free certainly increases its exposure and thus potentially increase its citation number. As an author, I want my work to be read widely. But this practice of paying for open access does raise a question. Can it create a situation where the work by the authors who cannot afford these fees will not be read and cited as much as those who can afford? What will be the long-term consequence of the nature of scientific inquiries, if we primarily read the work that are convent to find and download, because the authors could afford the price of making them “open”?
Here is an article on the citation advantage of OA articles: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040157. The benefits of OA articles are intuitive, whereas the long term consequences are less obvious and indeed very intriguing.