COVID19 introduced me to the “R number”, a way of rating the ability of a disease to spread. The higher the R number, the more infectious the disease. For example, with no safety protocols taken, COVID19 has an R number of approximately 3 in an unvaccinated population meaning that for every infected individual, three additional individuals will capture the disease. Incredibly, measles has an R number of 15 in a non-immune population. (source)
The R number is a helpful way of thinking about bookselling. As an author, you want to write books with a high R number, meaning that it is an “infectious” book that will lead readers naturally to share their experience of reading your book with others. In this scenario, you don’t even need to do much by way of publicity and promotion because readers are doing the work for you, posting reviews on Goodreads and Amazon, suggesting it to others, or even purchasing copies for friends. Books that have that kind of grassroots effect are rare indeed. But it is worthwhile for every author to be thinking what they can do through every stage of the process in order to increase the R number by making their book an infectious read.