It's always good to hear that agents and editors want material that is new, fresh, and original. But, as far as I can tell, you, Miss Snark, are the only person who really means this. I went to a publishing evening here in New York a while back, and an editor from a respectable mid-sized house said that it's not good to be too unique, because "then we won't know what to do with you." His statement has haunted me ever since; so much so, that I've put it into a recent short story I'm writing. Any comment about this, Miss Snark?
I think he was being sardonic. The truth is that the financial demands of a for-profit corporation require publishers to produce books they think will meet a certain threshold of sales. "Unique" is a scary prospect for those guys (just insert the word "untested"and you get a better sense of it).
Agents fork over expenses on a book to get it into submission, but it's the publishers who lose actual cashola if the thing doesn't sell. And they also lose market muscle. They've got the most to lose, you'll have to forgive them for being timid.
Editors are right smack in the middle of this. They have agents breathing down their necks with "the next best thing since Bible", and the editor in chief breathing down their necks for bringing in things that will sell, while all they really want to do is sit in their office and read good books.
The good thing, in fact one of the best things, about being an agent is you get to find those "too unique" projects, figure out how to cloak it as 'the next best thing' and then trot it around to a variety of places. You get to stay with something till it sells, rather than being forced to say no "cause we don't know what to do with it" and watch it go elsewhere.
There's a reason editors move to agenting a lot. That's one of them.