Many collages (specifically online collages) use books that can only be viewed online with no way to export content for offline viewing. To view your weekly readings you need a constant internet connection throughout the entirety of your study session. Even though we pay full price for these materials we have limited access. Many students do not have internet access available to them throughout the class and sometimes need to compete their assignments offline.
This is just an extension of the book scam colleges have been doing for years. Most of these materials are also proprietary and can only be purchased through the college in an attempt to create a monopoly on the materials needed for their courses.