This is one of the challenges in the market industry, remember to get your book published is not easy at all. Publishers are doing business in order for them to make survive. Therefore the are many reasons that might lead to your book not be published, may the book the book is written for specific audiences such as family, children or may be the book writing form does not fit to the market style of that field.
The book writers need to make sure before publishing they have done a proper research. The only way to do this is to go the library and bookshops. Compare and contrast the differences in the specific books of your book field and see if there are any other books like yours, or similar. Before even publishing get an editor to do editing for you and get a fit back. Compare the price as well.
Target market- there are many forms that you may use in order to market your book. The easiest one is to get all your friends, colleagues, past teachers, social media friends, etc tell them about your initiative. It is very advantageous to also use community newspapers, radio station, and social networks.
How to launch it, very easy as well. Usually South Africa has an art festival event every year, usually in Western Cape, Stellenbosch and Eastern Cape – Grahamstown. This is the great opportunity for self publishers to use this event to launch their work.