My observation is that looks definitely matter and sometimes in subtle ways. I was a hiring manager for years and consistently the panel of interviewers I worked with showed a bias toward candidates who were more attractive. It was subtle, but noticeable. Older candidates and overweight candidates with the same qualifications as others didn't make as favorable an impression. However, I saw it work the other way too. We had one young woman, a very attractive blond, who was passed over for promotion at least two years longer than she should have been (in my opinion). She was extraordinarily bright and very grounded, but frankly she looked like a 21 year old Britney Spears and the men in my conservative industry did not take her seriously.