I'm not sure why I've been blessed, but I have less than a ten percent no response on agent queries. I've even exchanged multiple e-mails with agents who have rejected me. I didn't complain to them, I thanked them for their time and consideration and gotten three or four thank you's back. I guess they don't get appreciated enough.
When partials and fulls went out I usually got something I could use to improve the manuscript, and I let some of them know that I appreciated the input and had used it to sell the project. Everyone of them wrote back a note of congratulations. No lengthy epistles, but it was hardly a form response, I'm not sure they have such form responses.
Now publishers are a different story; though when I wrote to withdraw the submission that had been with them for months I did get a few responses.
One E publisher had sent back several critical comments on the ms and then gone quiet after promising to get back to me shortly (a couple weeks). When they did not respond further after a nudge at +2 weeks, +4 weeks and + 6 weeks, I wrote off their no reply as no interest.
When I informed them I had withdrawn the submission, I got a response within the hour asking me what kind of deal I'd gotten and then informed they would have beaten the royalty rate if I'd gone with them. Well, if they'd gotten back to me at all, I'd have known that they still had an interest. And no, they said they did not mind simultaneous submission.
It's a funny game. Agents seem to be more relaxed generally speaking than are the publishers and respond very well to courteous behavior.
Regards,
Scott