I wasn't planning on this, but I think I'll start using the word "lulu" to mean self-published; I think it might stick.
What I meant to start out with was this: "You should not self-publish your book." I can say that, having self-published (excuse me, having lulued) my own book, and here's why:
The decision to self-publish, um, lulu was made for all the right reasons. My manuscript was good--several agents and publishers told me so--but as a humorist without a national platform, it was doomed to financial failure. Undaunted, I continued to send it out and received similar responses. Finally I thought, "well, if a publisher is going to loose money on it, then they are right not to publish it, but there is nothing stopping me from producing a copy to sell to my friends, family and fans."
As I said, a viable reason to lulu, so I set out to make the best manuscript I could. I culled my best and funniest essays, put them in a logical order, proof read them, proof read them again, proof read them again, had my wife proof read them, sent them to a professional proof reader, proof read them again and, you guessed it, proof read them again.
Then, with the help of my wife, I made a very professional looking cover, copied formatting from other books for copyright and title pages and all that extra stuff no one reads but would look out of place if I got it wrong. Then I proofread it all again and ran it through Lulu.
In all I sold 30 copies and gave away about as many; it was, on the surface, an enjoyable and rewarding experience, but here is why I think it should not have been done. When I read it over in book form, I found so many errors I cringed.
Nothing beats the editorial services of a professional publishing house.
And here's another reason not to lulu; the book was eventually picked up by a publisher and they found even more errors. Also, under their guidance, the chapters were rearranged and added to in a way the substantially improved the overall quality of the book, after I thought I had made it the best it could be.
Bottom line: lulued books are substandard. They might be well written, they might have even had all the spelling errors corrected, but trust me, if a publisher had worked on them, they would be better.
As I've said, I believe luluing has its place, but the prevalence of POD printers juxtaposed with the hard work and persistence required to produce a polished manuscript, synopsis and query letters and keep them circulating to agents and publishers makes luluing an dangerously attractive option.
Want to lulu your book? Fine. But keep these two things in mind. First, don't jump too soon; have you really made the manuscript the best it can be, and have you really, properly presented it to every place that might traditionally publish it?
And finally, don't expect too much; no one wants to buy a self-published book.