I'm on a humor discussion board at Amazon, and so many of the posts are self-promoting. Well... yeah... why not? However, the problem, in my estimation, is that we authors may say our book is hilarious, laugh-a-minute, the height of humor, totally enjoyable, and so forth. But is it? (Sure it is. I'm the author and I say so.)
My books have gone through a certain amount of editing and rewrite, and rewrite, and rewrite, but are they good enough yet? This is e-publishing folks, and e-publishing is SELF-publishing. Many inexperienced and untutored writers write "the end" on their dashed-off novel and launch the puppy the next day, complete with all it's warts. How is a potential reader to know crap from pure cream?
Potential Reader has no way of knowing. So my solution is to put my ebooks up for sale at 99 cents. Surely I will get more readers that way, because I'm assuming a reader's attitude will be, "Well, shucks, it's only a buck; what have I got to lose?"