You can, but that probably won’t work great. It’s like dipping a toe in a pool; feels chilly no thanks. But you jump in and soon find the water is fine. To experience a zyBook, one really has to jump in and fully experience it.
Plus, students don’t like multiple sources of the same info.
Some instructors initially survey students and find 50% want a hardcopy textbook. But remember the status quo bias. Also note that students actually don’t know what a zyBook is — we agree a hardcopy has benefits over ebooks, but a zyBook is not an ebook. And note that some students are now used to getting book PDFs illegally but free, so aren’t keen on having to subscribe.
Once students use a zyBook, surveys show nearly 100% prefer it over a textbook, realizing the interactivity is hugely helpful. Here’s a real quote: “My friend needs to learn programming. Can she access a zyBook? I used one for my class last semester. It was just such a perfectly designed online textbook.” We get hundreds of such emails every term.
Finally, we note that one reason textbooks are hard to learn from is they try to be both learning material and a reference, polluting the material with excessive topics. We focus on the learning part, and let the modern web be the reference (the web is often a better reference than any book).