For ease of reference, here is a quick comparison chart for the book formats currently available around the world. It is worth noting that while one format may currently be more popular than the other, there are pros and cons to each, and a good rule of thumb is to have options available.
| Digital | Audio | ||
| Physical copy | yes | no | depends |
| Production cost | high | low | depends |
| Shelf life | short | potentially infinite | potentially infinite |
| Royalties | very low | high | depends |
| Risk of theft | low, but possible | virtually guaranteed | very likely |
