I couldn't really tell you why aspirants seek Theta Nu Xi, only why I sought Theta Nu Xi. I saw a professional, strong and meaningful organization and was well impressed. On the other side, I see what it takes to present the qualities I mentioned.
Theta Women are always out in the community helping others and meeting people. We have a high standard for appropriate womanly behavior (though we're all human and make some mistakes.) But, especially when representing our organization, we maintain our professionalism. I can't stress that enough - be a professional. As I've said before, the most successful organizations are well-run businesses at the executive level. The rest of us benefit from the hard work of our inter/national boards.
Theta Woman are also taught to be discreet (again, we're human and slip up occasionally). We do not go around airing out our business between Sorors nor do we get huffy and trash-talk our organization. We are also HUGE proponents of Greek unity. We believe that each person can find her own home even if it's not Theta Nu Xi and we appreciate her for that. I'll say right now that I encourage any of you GCers who have not met the Theta Women on your campus - if we have arrived on your campus! - to get to know them and work with them on events and such.
I think one of the key elements to Theta Nu Xi's expansion is our great love for our organization. I believe women see how deeply we care about each other and how loyal we are to our Sisterhood. People want to be part of a supportive group anyway - that's kinda how we are psychologically.
When you DON'T go out searching and, instead, allow your actions and words to reflect the genuineness of your Sorority, people will take notice and become interested.