Dryad, one of the largest public data repositories in the life sciences, last month imposed modest fees on researchers for archiving their data (see http://datadryad.org/pages/pricing). We believe that this strategy is misguided. It will further discourage researchers from participating in public data archiving.

Authors' participation in archiving is already low, and many fail to comply with journals' policies in this regard (see, for example, B. T. Drew Nature 493, 305; 2013). Even when their work is publicly funded, researchers can be reluctant to share their data through public archives because they lose priority access to it. And compensatory benefits — such as those arising from increased citation of their papers — are not always forthcoming. Requiring scientists to pay fees from their own research funds is adding one more hurdle.

Of course, public repositories of data need to be maintained and paid for. But rather than billing researchers, costs could be met using more subtle methods — much as they are for 'free' restaurant bread and hotel Internet access. Payment could come from private- or public-sector grants, institutional contributions, dedicated funds quarantined by grant agencies, or from partnerships with journal publishers. That way, funders' budgets or publishers' profits would foot the bill.