@charliegolf,
There are several reasons. But for one; if you want people to do what you want them to do and accept things they normally might not, is when you have something they want. In this case (the hope for) a base they (so badly) want. You lead this person a string and say he might get it in time when he or she will do what you want and look what you can achieve and make this person do or accept. This way you keep better control over the person!
Ofcourse this is just my opinion.