This document discusses data metrics and incentives for data sharing. It presents several models for data sharing, such as publishing datasets on personal websites or through data repositories and journals. It also conceptualizes different types of potential "data metrics" like citations, readership counts, downloads/views. However, data sharing is currently hindered by a "vicious circle" where researchers lack incentives to share data if they cannot get credit. The document recommends developing reward systems based on data metrics, standardizing data publications, reducing costs/negative perceptions, and coordinating technical infrastructure to break this circle and encourage data sharing.