Your query was successful. Congratulations! So, the agent asks to see a partial/full ms and you send it off in the requested format with a short note included either in the email thread or with a proper subject line (see links if you haven't been following my February Requests series--FAQs to come Tuesday).
Then you wait.
Step away from the Girl Scout Cookies.
How long should you be waiting to hear back? Firstly, if you've done your research, most agencies and personal agent blogs give an amount of time you should expect to hear back by. It can be anywhere from 6 weeks to 6 months, and some say that if you don't hear back it's a no (generally that's only for queries, not manuscript requests).
So wait that amount of time before stressing. Actually don't stress at all. Just because we didn't answer, doesn't mean we hate you. It means we were so busy we didn't have time to get to your ms yet. Most likely, it's sitting happy on our e-reader, waiting, just like you. However, there is a chance it got lost and never made it to the agent. It happens. Sometimes we forget to answer. Sometimes we think we answer but actually didn't.
That's the reason for The Nudge.
The Nudge, when done properly, is perfectly acceptable and a common practice. Don't sweat it. Don't think, "OMG this agent is going to HATE me for bothering them."
No, no, no.
Here's an example of a Nudge:
Dear (agent's name),
I sent you (so many pages) of (title, genre) on (date). I'm just following up to see if you've received the materials and if you've had a chance to read it yet. Our previous correspondence is below. Thank you for your time. I look forward to hearing from you.
Or some slight variation. But short, sweet, to the point. No flowery apologies, no badgering, no "look what I've done since I sent it to you, fancy awards, yippee!". If anything of significant note happens, yes you can slip it in, but by this point, it won't change my mind to whether I love your ms or not.
By the way, my response time is about 2 months. So if you haven't heard from me in 2 months, you may nudge me.
If you have any questions for my Requested Manuscripts FAQs post on Tuesday, please leave them here or on Twitter and I'll do my best to answer them all. Thanks!