I interviewed with Microsoft in university. After a half-day on-site interview I was taken into a room and a recruiter made me an offer. She expected an answer

I interviewed with Microsoft in university. After a half-day on-site interview I was taken into a room and a recruiter made me an offer. She expected an answer on the spot. The recruiting staff had told me a week or two beforehand that this was their process. I didn't know the details of the offer until the day, though.