Updated January 2019 – They have been closed to direct submissions for over a year now. The link to their submission guidelines is broken.
WITNESS Impulse is a digital first imprint of Harper Collins. They publish a wide variety of mystery novels, including digital editions by some of the most famous mystery writers of all time, including my personal favorite Agatha Christie. However, they also publish new and emerging authors. It is important to note that usually publish print editions of their books. However they always publish the digital version first.
According to their website “The average number of books sold for all Impulse titles on sale for at least six months is about 15,000.”
WITNESS Impulse authors receive 50% royalties after the first 10,000 copies sold, and will start at 25%. They are also very marketing focused. They really try to sell as many copies of each of their books as possible.
They are very new author friendly for a division of a major publishing house. The link for author submissions is very easy to find and their instructions for submissions are easy to follow.
To submit you have to complete an easy to fill out form that asks simple questions about the state of your manuscript. They also request a synopsis, the best scene, and various other specific pieces of information. The manuscripts they publish vary in length between 10,000 and 75,000 words (although they can be longer than 75,000 words, they cannot be shorter than 10,000).
I suggest typing out the answers to the more complicated question first and then cutting and pasting it into the submission form. You are less likely to make errors that way and also you will be able to save your work for later if you have to submit something similar to another publisher.
To learn more visit their website here.