I still remember how surprised I was to get a second book and 'gratis' when I bought one of my Dutch study books as a recently arrived foreigner to The Netherlands. Then I was explained that it was only during the Dutch Book Week.
What I just discovered, many years later, is that on the Sunday during the Dutch Book Week you can use the book you had received as a present instead of a train ticket. I decided to go to Groningen -as far as you can get and still being in The Netherlands-. It was a full train in both directions and most of us were carrying at least one book: our free train ticket.
The Book Week is already finished but here to train impressions with people carrying or reading their Joost Zwagerman ' s Duel ticket-book.