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.
(..) from Skynet. It says everyone in this room will be dead by week's end. You're number two on the list. -Well, who's number one? -An unknown. A civilian. Kyle... Reese. OLSEN : Jericho, come in. Come in, Jericho. JOHN: Barnes. (..)2009 Terminator Salvation