I think Georgetown is a lot like UCSD in how they handle acceptances in their rolling admissions process. In both cases, I think they offer a small number of acceptances immediately following the interview, and place a large number of applicants in the "competitive applicants" or "acceptable" pool. This means that they will not have filled up their entering class by the time the interview season is over, and therefore allows them to select individuals from these pools to offer admission. I don't have solid numbers to back this up. I'm basing this purely on the fact that both schools have a relatively small number of accepted applicants to date.