Although a relatively recent phenomenon, measuring the usage of published research has rapidly become one of the most important ways to evaluate the relative value of different publications. Libraries and publishers are also investigating the impact of interface and technology provision in improving resource discovery and content usage. Demand for such data is increasing throughout the industry, partly in response to greater scrutiny of return on investment. As a result the techniques used by publishers and librarians to promote and evaluate usage are also developing. This paper looks at some of the methods currently adopted and examines the issues faced by the industry in driving forward the application of usage data.