I think it's quite a big factor. One girl I had a crush on had a very identifiable 'smell', so much so you could walk into her room and be hit in the face instantly by it. But ofcourse, if it wasn't a nice smell, I doubt I'd have had a crush at all.
That said, who would be attracted to someone who doesn't smell good?
That said, who would be attracted to someone who doesn't smell good?