The market for college textbooks is an interesting one. One thing that makes it unique is that the person who chooses the textbook (the professor) is not the person who purchases the textbook (the student).
Therefore, much of a textbook publishing company's marketing is geared toward college professors.
Most publishers of economics textbooks have developed (or have partnered with other companies to provide) online homework-management systems.
The one that goes with this textbook is called EconPortal, as you may already know if your professor is using it.
Explain how a homework-management system might benefit a professor. What impact might a homework-management system have on switching costs?