If I took a deposit, do I have to rent to the person?

[Brad Thomas]

After going through showings and application, my business partner told a woman she would not relist the house (would pull the listing from Craigslist) if woman put down $500 good faith money to hold the place (rent is $1400/mo). Move in was 6 weeks away at that point. We just received the deposit -- 4 weeks later and only 2 weeks until move in. Annoyed (before the deposit check arrived), I relisted the place a few days back and have several hits worth pursuing. Do I have to rent to the original woman? Should I?