I'm slooowly working my way through a backlog of queries and requested manuscripts. I came across this in one of the queries today: Please respond only if interested.
I understand the query sender's motivation: it's hard to get those rejections.
But here's why you do not EVER want to put that in a query: if you can't stand rejection at this stage of the game, you're in the wrong game.
Here's just a sampling of the kind of rejections you have yet to see:
1. editors not buying the book
2. chain stores not stocking the book
3. libraries not buying the book
4. 1-star posts on Amazon cause a reader thinks the ebook price is too high
5. publisher not picking up your next book
6. publisher not picking up your third book
7. publisher not picking up your fourth book
This industry is nothing but rejection. You either figure out how to deal with it, or you need to get out now. I'm not saying you have to love it. I'm certainly not saying you have to turn it into some sort of sadistic motivational tool. You figure out how you best deal with it, and start practicing.
Every writer gets rejected. You may as well get used to it now. Cause even if I am interested in your project, if you send off signals of "I'm a delicate flower" you're going to get..yup.. rejected.