When I first began writing books, self-publishing was considered illegitimate. These days, self-publishing is happening more and more often and gaining respectability by the day--but it does leave the self-published author with the question of how to do the publicity work that otherwise would be the job of the publisher.
I'm still trying to figure that out. It's an especially difficult job for an introvert, where even the act of saying "Hey, my book's good, you should read it" is fraught with terror.
By the way, my book's good and you should read it.
How To Go To Hell in 10,000 Easy Steps