Ask your friends who you never thought would join in a million years, to join. That's where my little came from.
Obviously I don't mean your friends who are virulently anti-greek, if you have any...but the ones who might be interested but didn't want to rush. This is where summer school comes in. It's a more laid back environment and people open their minds to things they wouldn't previously. I was in summer school with my little one day and she just came out and said to me and another sister that she would love to pledge us, and she did the next fall.
Good luck!!