其他摘要：Electronic journal publication, speeded up by the advance of the Internet age, became common in the world of the academic journals. Among the various advantages of electronic journals against journal publication in traditional print style, there is a large point that the binding of issues has nearly vanished that we can now easily handle journals by each article. Accordingly, sales by single articles, called such as pay-per-view, have appeared. Services by pay-per-view are also becoming available at sites other than publishers. We have assorted those pay-per-view services into three groups by supplier, i.e. publishers, aggregators and secondary database services, and illustrated out the characteristics of their services. Furthermore, brief analysis on cost performance is given.
