We recently had a rather large party in the parking lot of my fraternity house.
As social chair (party planner) it was my job to set up the party and make sure we were not breaking University rules.
For risk management reasons, not worth delving into here, we need to submit a guest list before the event.
So, part of my responsibility is to collect the names of all the guests the people in the house invite.
Not an overly difficult task but getting this information from 70 other "college dudes" can test even the most patient man's patience.
To keep reminding people of my need for names I would periodically send out emails over the email server.
Each one had a different subject line because I wanted to see what kind of response I would get.
The first was merely "Island" (the name of the party) and the request was in the body of the email.
I received 7 emails back.
The next was "Invites. Email them to me even if you haven't used all 4. Thanks bros."
I received 21 emails back. Improvement!
The last email I sent (two days before the list was due) read "Invites. Yours. I need them."
35 people emailed me back.
Even more interesting I received emails from people who had already given me the names of their invites.
While the proximity to the date of the party for the last email was closer I think there were multiple things at work.
First, the email server labels the email from me to the individual, not the group.
This made people think I was emailing them individually because they had not submitted names.
Second, the line was very direct.
The first two emails were polite requests the last was a command.
Third, after harassing people multiple times they eventually caved.
Doing things like this with such as large group is a great way to learn about how your copy works best.
You can discover what makes people tick and what falls flat.
If you think of how many emails you send in a day it seems like a no-brainer to use the subject line to hone your headline writing skills.
Please don't go off and spam a bunch of people but if you have a situation like this you should exploit it.
You can bring lessons from anything in your life into your work.
Play around with it and see what kind of response from people.
It can't hurt and it'll probably help.
note: The party went very well. Thank you for asking.