I completed my work almost 2 years ago. Initially, my book focussed on MS Excel 2010. I had approached reputed book publisher in Chennai. They are also happy with my manuscript and table of contents. I signed the contract with them. But later on, they told me that they are not ready to publish my work. I convinced them, and then I updated my work using MS Excel 2013 Preview (at that time Microsoft released its newer preview version).
I had spent a few months to complete that work. Again, no response from the publisher. At last, they denied to publish my work, reason: budding author, no budget, blah, blah, … blah. Later, I had approached 10-15 publishers, but they also denied to publish saying that I am a budding author.
Finally, I decided to go for on-demand publishing by spending some capital amount :).