Vanity or “Subsidy” book publishing is popularly known as Vanity Press. This type of book publishing is different from conventional publishing.
Vanity press requires the author to finance a part or all of the total publishing cost. This includes the marketing expenses for the promotion of the book. On the other hand, the conventional book publishing still follow the usual protocol. First, it accepts the manuscript then reviews it. If the material has commercial potential, the publisher will pay for the publication and endorsement of the book. In vanity press, the publisher has little risk because it has either a small or no investment in the publication of the book. That is why it accepts as many manuscripts as it wishes.
Amateur writers are attracted to this kind of publishing, because they are given all the opportunities that conventional publishers cannot provide. Vanity publishing mostly acknowledges unsolicited manuscripts. Meaning, an author need not seek representation from literary agents.
Time is a plus. Since, authors do not wait for their manuscripts to be reviewed and approved. They have control on the date that their book is launched. Of course, it depends on the financial capacity of the writer. Also, there is no censorship. As long as the contents do not convey too much obscenity or ruin the image of the publishing house, the book will be published as it is written.
If a writer releases a book through a vanity publisher, there a necessary chance to build his or her reputation in the book industry, and learn the business side of literature industry. Many function as their own agent. Thus, they can schedule their own tours, make contacts and directly receive feedback from readers.