what they look for?

What do sororities at USC generally look for in a pledge? Do they look for someone that comes from a rich family? What kind of recs look good to a sorority? How much recs do you need and how important are they? If you're very involved in campus, will that look good? Cause I want to try figure skating, cheerleading, volleyball, and a political club when I get to USC? I read somewhere on this site that sororities can tell who they want to cut just by looking at their applications? Is that true? What looks good on an application? Thanks for the help! :)