Data on usage events can be the basis for a variety of services, the most obvious being the generation of metrics similar to COUNTER statistics. A report from a small review study supported by JISC outlines one approach to sharing such data. Based on a consultation workshop, and drawing on the architecture proposed by Johan Bollen and Herbert van de Sompel in 2006, this report proposes a format based on OpenURLContextObjects shared over OAI-PMH. Other projects are taking this approach forward, eg the JISC PIRUS project (article-level COUNTER statistics from publishers and repositories) and the DFG OA-Statistik project (a German infrastructure for standardized collection of usage data). I know some have argued that a lighter approach to sharing item-level usage data might be better, and I also wonder whether it would be helpful to describe some of the use cases for sharing usage data, other than the generation of metrics?