Self-publishing refers to the situation where the author is the publisher of his or her works, i.e. the author takes full responsibility for the publishing of his or her book, and bears the legal and financial risks associated with that.
Self-publishing does not coincide with do-it-yourself publishing, where you are capable to produce the final product all (or almost all) by yourself. The connotation in this case is rather a non-professional product.
In contrast self-publishing as used here implies a professional product, often indistinguishable from the ones produced in a commercial print house. Therefore it depends on a number of professional services and/or service providers (to complement one's individual publishing-related abilities, if any).
Why publish oneself?
There are numerous reasons why you revert to self-publishing. A representative sample is presented below:
Limited sale potential
There are numerous topics which deserve consideration, but are of somewhat limited scope and therefore with limited sales potential. Examples are scientific monographs, dissertations, regional and/or local history, family history and/or photoalbums. Most of these are generally produced in short-run quantities and this makes sense. Why produce thousands of a book, when you might only distribute at most one or two hundreds? Or, carrying the same argument even further, why produce even a hundred, when you need only a few dozens? Or even less?
Unless you are determined to make a living on writing why even make an estimate of your potential reader community? Very often you are willing to spend a certain amount on your idea, or you have found one or more sponsors willing to support your writing projects by sentimental or community-centric reasons. It is too much to expect of these noble benefactors to organise the production of your opus. Just say thank you and do it yourself.
Making money is not the only reason to publish. Other powerful drivers are sharing or leaving a legacy. Publishing a book is also a wonderful way to express yourself and communicate with others.
In these cases you do not necessarily hope or expect to make a profit but rather to succumb to the writing urge or serve the community, family, collegues, etc.
You are onto something great, a niche publication, but you are not known to the publishing world and, consequently you cannot get close enough to a publishing contract, or even to a consideration.
And then why sign with a publisher for a 5% of the proceeds, when you may gain from 50% to 300% or more?
Anyway, you can test whether this is so not by going all out with e.g. 1000 copies, but by 10 or 100. If you turn right, you still have the option of large-scale printing/publishing, you may well be contacted by publishers willing to acquire your publication. The more successful the initial test is, the better prepared you are.
A book is a brainchild of its author – you. Often advice and editing are wellcome, but self-publishing gives you complete control – all decisions are yours only and you need not compromise with third parties.
As publisher you own all rights of the book, conversely the publisher owns most of the rights and the freedom to use them in his own interests. If you believe that you are the one who can best protect your own interests, then self-publishing is for you.
Digital printing and short-print runs
We know that with traditional press printing there exist print runs – short print runs – for which the use of a commercial printer is infeasible. That was the major reason self-publishing was associated with poorly looking do-it-yourself products (e.g., typewritten or produced and bound at a copy shop), which understandably could not reach out to any significant audience, beyond friends and relatives.
Self-publishing became feasible with the advent of digital printing (e.g., the laser printers and digital copiers) and the Internet (to be discussed separately). Today's digital print houses are capable of producing books and other printed materials practically indistinguishable by quality from the products of commercial presses. They also can produce these at short print-runs which are prohibitive economically for the traditional print-houses, but the initial investment for which is reasonable for the self publishing author.I
Print on demand (POD) or publish on demand implies that new copies of a book (or other document) are not printed until an order to that effect has been received. POD is an outgrowth of digital printing, because it was not economical to print single copies using traditional printing technology, e.g. offset printing.
Many small printing houses or academic publishers, including university presses, use POD services or service providers. Larger publishers use POD for reprinting older out of print titles or test marketing.
Publishing on the Internet
The financial demands on the self-publishing author have become even lower with the advent of the Internet. With today's widespread computer literacy many computer users are perfectly capable of producing good quality electronic books themselves. With computer readable books and the Internet the reproduction costs, which were the major obstacle to the self-publisher, become practically insiginificant. And most of all, with the use of the Internet global marketing is practically at the fingertips of the self-publisher.