The last decade has witnessed an enormous growth in the number of open access journals. The online mode of publication has given significant advantage to the publishers, in terms of production cost and this has led to the mushrooming of many new journals in scholarly publishing. For researchers, the increase in the number of journals provides bigger platforms for sharing their results. More importantly, the open access nature is expected to increase the visibility of their work and hence future citations. However, it appears that there are significant challenges ahead for the publishers as well as researchers to keep a sustainable ecosystem of both open access and subscription based models. First of all, the open access model puts additional financial burden to the researchers. Almost all R&D organizations have earmarked funds for subscription of journals and is being done annually by the institution. On the other hand, uniform policies towards payment of article processing charges (APCs) are not yet evolved. Some are of the opinion that the outcome of public funded research should be freely available and hence funds can be earmarked for open access. However, the onus of generating funds lies primarily with investigators, which puts additional constraints to the researcher. There are also apprehensions that some open access journals may compromise the peer review process, owing to the monetary interest arising from APCs. Under such circumstances, it is difficult to make a judgment whether APCs should be promoted at the expense of research funds or subscription.
Another point of concern in open access publishing is the visibility of the journal. Though the articles are free to access, it is important to ensure that the journals are included in the searchable database. Unless the articles are reflected in the search tools, the accessibility does not add value. Open access publications also face challenge to establish its credibility. Most subscription based journals have established impact factors, and that is often used as a measure of the quality of the journal. Such assessment of the open access journal requires some more time, as most of them are relatively new. Researchers prefer to publish their work in an established journal to attract maximum attention of their work. There are also new hybrid models that are being explored such as "read and publish" license which enables publishers to have a common agreement for subscription as well as APCs. It appears that both open access and subscription based models will continue to coexist. However, the sustainability of open access publishing will depend on future policies towards payment of APCs through research funding and maintaining the quality of the journal without any monetary interest in generating revenue through APCs.