via emarketer.com
Notice that women are most like to respond to an ad that involves a sales offer or a special promotion code (I know those work on me!) My feeling is that this same principle applies to email offers.
If you are attempting to compel female response to an offer, this might be worth testing: have one landing page that makes the offer outright, and have a second one that requires the use of the code to receive the offer. How fun would that be? Of course, no one likes to feel manipulated, however, it's an age-old direct marketing principle that allowing the responder to interact with the offer is more compelling than just giving it without requiring any action on their part.
