It may not be a gift to you, but it can be a gift to other customers/users who can build more informed opinion on whether to buy your book (or any product) or n

It may not be a gift to you, but it can be a gift to other customers/users who can build more informed opinion on whether to buy your book (or any product) or not. 1-2 start and 3-4 start reviews capture different parts of the distribution of user experience, and they often capture different sides of some product.