1. Not being amazing - The single most common reason for novels not being published is that they are simply not amazing. Publishers have an almost unlimited supply of writers looking to get their books in print, so why would they publish anything but the very best writing? Your novel being good is just not good enough.
2. Producing a rubbish pitch - Many writers spend years writing a novel and then look to knock out a book proposal in a matter of hours. Writing a book proposal is an art. In essence your query letter and synopsis are sales documents convincing the publisher that you are a serious writer, who understands the market place in detail and has written an excellent book.
3. Not doing any research - Failing to do the research needed to write your book, or find the website that offers you the best advice on writing a book proposal, or pick the most suitable agent, or pin point the ideal publisher or identify the competition all equal failure.
4. Not being differently different - Novels take a long time to write and the publishing industry moves (relatively) quickly. Churning out books that are the same as the bestsellers when you start writing is a recipe for disaster. Your book needs to clearly fit into a genre but still be differently different enough to give it a unique angle in the marketplace.
5. Giving up – Only by giving up will you ensure that your novel will never get published.
6. Crappy online presence – Publishers are looking to sell a product, and the writer is part of that product. Ask yourself which book you would published: a good novel from a first time writer with the only online presence being a personal Facebook page – OR – a good novel from a first time writer with an active blog, a sizeable Twitter following and a great Facebook fan page?