Getting Sororities to Give You The Time of Day

[excelblue]

My chapter has been trying to set up socials with the sororities, but it's been extremely difficult to get most of them to give us the time of day. Asking early only gets us polite rejections.

So, I'm wondering: if you're in a sorority, what factors do you look for when deciding who to have socials/invites with? I understand that all chapters may vastly differ, but I'm trying to guage if there's any one particular thing that my chapter's sorely missing when trying to arrange these things.