A university bookstore, which is operated by a well known bookseller, is selling subscriptions to a "homework help and textbook solutions" website. The subscriptions appear beneath the university logo and the words "University Official Bookstore." If you select a course, the required books appear. Below that, it says "Optional" and the subscription is listed.

This seems to imply the subscription is endorsed by the instructor, very probably without the instructor’s knowledge.

Is this marketing by the bookstore ethically acceptable?

This bookseller operates over 700 campus bookstores.

Update: The bookseller has changed the page to read "Bookstore Recommended" which seems more appropriate.