The Digital Object Identifier (DOI) is a technology that helps make information more discoverable through persistent linking and interlinking. It has been adopted universally across the scientific/technical/medical (STM) publishing sector and more recently is being adopted in other sectors of publishing and other industries. All publishers we studied achieved measurable benefits from the DOI, and publishers in the process of implementation expected similar results. Publishers experienced benefits in one or more of the following ways: increased discoverability of their content, increased content sales, and reduced costs in product development and maintenance. Increased discoverability of content via cross-linking. Publishers using DOIs have experienced significant increases in inbound traffic to specific pieces of content from a variety of sources: search engines, aggregators, and other publishers’ content. This white paper is the bi-product of research originally commissioned by a major publisher to assess the opportunities and financial returns for using the DOI within its various publishing businesses. The findings are based on interviews with publishers in the U.S., Europe, and Australia.