The E-Books Observatory project of the UK's Joint Information Systems Committee (JISC) aims to provide higher-education students throughout the UK with access to a number of popular textbooks in digital form free at the point of use, and then measure their usage of them. Subject areas covered were business studies, media studies, engineering and medicine. Surveys of users were conducted in January 2008 and in January 2009, to measure changes in usage as a consequence of the availability of the e-books. Focus groups of users have also been held. The usage of these e-books has also been monitored by deep weblog analysis, which will continue until Summer 2009. It is believed that this is the largest study of E-book usage yet mounted. Both the questionnaire surveys attracted over 20,000 respondents. Preliminary conclusions are given here, and they suggest among other things that electronic availability of textbooks will not impact sales of the printed books because print and electronic versions are used in different ways.