Actually, per some past threads/posts by socrates, he mentioned that it can hurt the company's rate negotiations if they use up too many or too few rooms. If I remember his posts correctly he mentioned that since hotels have a fixed number of rooms, they don't want one company monopolizing too many of their rooms/night. Since I'm not an insider in this industry, I couldn't tell you which tends to be more limiting to companies, using too few a number of rooms or too many when they are re-negotiating rates. Maybe socrates can give us a hint on that.

The main point, though, is that hotels and companies negotiate those rates based on an estimated low end and high end usage number. If either of those turn out to be a bad estimate, then when re-negotiations occur, the rate will probably change as well. So its not always in the company's best interest to allow everyone to use their rates.