There are no print or distribution costs for eBooks. (bookworks.com)
They could charge premium prices for discs and packaging and they had to to cover the manufacturing and distribution costs of discs and packaging. (geeklawblog.com)
Authors should be getting larger royalty percentages on e-books because of lower distribution costs, so the publisher doesn't need to take as large a cut to cover their costs. (tracycembor.com)