Show You Know Your Subject
As experienced professionals, we can see if a writer has talent, but we might not always know how marketable a book idea from this author really is. Because many of our authors write books on practical nonfiction, we know that market very well. But we might also be intrigued by a proposal on, say, vampires or the Knights Templar or the real King Tut.
Of course we know how popular those subjects are. And we know which publishers are likely to be interested. What we don’t know is how your proposal stands out from the crowd, and why the audience that wants books on vampires or the Knights Templar or King Tut would pick up your book instead of somebody else’s.
You are the expert here. And “expert” implies being aware ...