Men, how do you REALLY feel about a woman that gives it up easily?

In college I've encountered a multitude of my women counterparts that have quickly with men they haven't known, but for like a week or less (some within the day)! Does it make a difference if it's men that attend the college or the size of the student body? In the real world I'm hoping it's less but that outlook doesn't seem likely. Honestly men, if a woman will have with you and you haven't known her for long what do you truly think of her?! Especially out of the college atmosphere...is it possible to date her as in make her your girlfriend because I've seen this situation too (and no the girl wasn't pregnant)?