I've closed a few deals over the years by researching potential clients' interests and then ringing their bells, so to speak, too. Funnily enough I've also been doing a fair bit of research recently on one particular forumite and have noticed that he has recruited an individual into his company who's personality traits/failings very closely mimic his own.
Re this thread though - If the interviewer also has a beard it may help. If not then shave it off. And, if you know who the sole/lead interviewer will be then its always a good move to find out as much as you can about him/her as well as about the company.