I am unpublished young novelist who has few writing credentials to his credit. In my query letter, rather than reflect on my inadequate pedigree as a writer, would it be wise to play up the marketability of my thriller? I believe it has a large audience that has largely been ignored by fiction writers up to this point.
Chances are I know a lot more about marketing thrillers than you do.
Nothing makes me sneer more quickly than some whippersnapper telling me about his great "new" idea...the same one that seventeen publishers have been doing for a decade.
Focus on your writing.