Incentive is a great idea. People tend to respond more when they know they're getting something in return.
Also, did you try to join the online forums where most of these women hang-out? Women like to help each other, so if you post your message with honesty, that you're doing a research if this business idea of yours is viable or not, you should get a decent number of responds.
Do you have a budget for mailing list? It's legal and not only you get their e-mail adds, you also get their contact info once you decide to go forward with this idea.
- Jean
"A ship in harbor is safe, but that is not what ships are for." - William Shedd