If you've never been published before, you're an 'unknown quantity', so you're going to have difficulty selling your first novel.
('chiefly US') The 'big unknown' [=the important thing that everyone would like to know] is how investors will react.
A 'fear of the unknown' kept her from changing jobs.
(..) Hey, Speed Racer, you're welcome to leave anytime. Well, for the record, Superdad, I'm not hiding with you. I'm hiding out with that big guy. Sensei, with your fate unknown, Bumblebee has held command, despite his complete and total lack of anything resembling warrior discipline. He's like a child. (..)2014 Transformers: Age of Extinction