If you are a guy—especially (but not necessarily) if you have a glimmer of personality, intelligence, or looks—you are way ahead. There are girls to go around, and around again. The student body is notoriously described by those both on and off campus as shallow and materialistic. This is obviously not universally accurate, but BU certainly serves up its fair share of these sorts of individuals.
The selection of suitable mates is certainly slim. If the good ones aren’t taken, they are usually gay. In fact, many girls here have relationships with people they met off campus (yet another benefit of city living). Finding people at such a huge university is easy; finding your niche, however, takes some time. Move around, get away from the University setting, and be open to friendships (romantic or otherwise), wherever they might occur.