I guess in some ways, Otterbein was a "suitcase college" because so so so so many people came from these wee towns in Ohio and went home on the weekend. It was almost creepy. Us rare but hardy out of staters enjoyed the weekends. But OC also has this weird family thing, meaning we get lots of 3rd and 4th generation Cardinals going to school there, and most of those have some Greek affiliation in their history. Plus people tend to be freakishly involved in campus life (for better or worse).
So I guess what keeps people around is the "tradition" aspect of it, but thats not going to help you just starting out. How many other groups are there on campus (both Greek and non-Greek)? Maybe since you're a bit down on man-power at the moment (but use those alums!) you could pair up or bunch up with another group and hold a larger event. But also keep in mind that your most likely pool of candidates are people you already know on campus. By diversifying your pool by looking at all class standings and not just freshmen, you can find some girls who already have the skills to be successful sisters.
and check out the recruitment board
