The library can only purchase ebook copies of materials made available by publishers. Unfortunately, most traditional textbook publishers do not sell electronic versions of their works to libraries for institutional licenses and access. In practice, this means that by and large the library cannot acquire electronic textbooks from major publishers, such as Pearson and Cengage to name a few, even if these materials were made temporarily available for free on VitalSource.
You may have heard of a textbook business solution from VitalSource called "Inclusive Access". In this business model, materials are adopted across an entire university and sold to students at a discounted price, usually negotiated by the university, the campus bookstore, and textbook publisher or provider. While inclusive access can offer cost savings and day-one access to students, access to materials in this model is temporary, and students are billed automatically for textbooks unless they opt out. In this model, textbooks are still purchased by students, and the library does not play a role in providing access.
For further reading, we recommend the chapter "Inclusive Access: Who, What, When, Where, How, and Why?" in The Evolution of Affordable Content Efforts in the Higher Education Environment: Programs, Case Studies, and Examples.
