For electronic journals, total downloads can predict number of users

Results from two multiple regression models involving HighWire journal subscriptions in 2003 for 16 participating universities in the United States, United Kingdom, and Sweden indicate a highly predictive relationship between the number of article downloads and the number of users-meaning that the size of a user population can be estimated by just knowing the total use of a journal. The relationship is consistent over time and across institutions and appears to be unrelated to the subject, size, or popularity of a journal. It is not consistent across publishers, however, suggesting that an "interface effect" may exist. The development of a Project COUNTER standard to deal with extreme or abnormal journal usage is necessary if we wish to compare the performance of journals across publishers.