In New York apparently there is a thriving business which links every possible marketing opportunity onto e-books, same way as Disney does with movies.
If the book mentions a hotel and spa, sell the spa water; if it is located somewhere exotic, travel is obvious.
So the book becomes incidental to the Product, as far as the profit oriented marketers are concerned.
There is something similar going on with a South African writer who has a new book coming soon; in the world of her book everyone has 'companion animals' like sloths or ant-eaters or monkeys which they carry around everywhere. These seem to be there to provide a marketing opportunity for no doubt expensive 'licensed' stuffed toys of exotic and unusual species not often thought of as pets and so unlikely to be already produced by competing toy makers.
So I am sorta on a parallel track with 'Eland Dances'- same idea with an animal connection, but more realistic and less of the commercial possibilities.
The difference between say 'Lion King' and 'Born Free' perhaps.