You will still receive royalties from the sale of your book, if your book contract provides for them. Although a digital version will be made available to anyone for free, the publisher will continue to sell physical copies and premium digital versions. You will receive royalties arising from these sales. The Open Access version has the potential to act as a kind of advertising for the other versions of your book and to raise your book’s profile in a digital world. Books that are made available on Open Access licences often sell better than their traditional equivalents.