'Spotify for e-books' is effective marketing http://www.cbs.dk/en/research/cbs-publications/cbs-research-reporter/news/flat-rate-on-books-illustrates-effective-marketing-innovation?frontpagesliderOnsdag, 29 april, 2015 - 14:15
http://www.cbs.dk/en/research/cbs-publications/cbs-research-reporter/news/flat-rate-on-books-illustrates-effective-marketing-innovation?frontpagesliderOnsdag, 29 april, 2015 - 14:15