Note 6. A traditional publisher will require 12-18 months to publish your book, on average. Figure another 6-12 months to secure a literary agent (if you can). So with traditional publishing your manuscript will not see the "light of day" for a long time. In addition, with all the publishing acquisitions by global enterprises, your project could get caught in the middle of a merger and be abandoned altogether.
If you self-publish, you can have your book overnight in some cases. It's a whole different ball game.