Gotta disagree with you, bolingbaker.
I'll use my campus as an example. There are 5 sororities. 4 are well-established nationals; the fifth (mine) started as a very small local sorority. The 4 older chapters are all near or over total, so that only AEPhi is typically eligible to hold COB rush. The "big four" typically have membership numbers in the 90s and 100s; AEPhi has grown from 10 women (when we first went national) to about 40.
During formal rush, a lot of women don't give AEPhi a chance because of our low numbers; they tend to set their sights on 2 or 3 of the "big four". A lot of them match, and that's great. Some of them don't match. So AEPhi invites them to informal rush, and some of them join. (That's where the aggressive recruiting comes in.) Others decide AEPhi isn't for them (or we decide they're not right for AEPhi), and they wait until the following fall to go through formal rush again. And still others decide to give up altogether on joining a sorority.
Then there are women who, by the time they get to pref, are cross-rushing AEPhi and another sorority. If both sororities could offer a bid to a given woman, she'd be very likely to go with the older, bigger house. But with the bid matching rules in place, she might match to AEPhi, join, and find she's just as happy there as she would have been in the other sorority.
If the rules weren't there, a lot of women would have joined one of the other sororities without giving AEPhi a chance, and my chapter might not be here today. As it is, the chapter is growing, and will soon be the same size as the other sororities on campus. And these women are as happy in AEPhi as they would be in a different GLO.
Just my $0.02
