Are you, and your fellow musicians, really good?
Does your outfit know and perform at least 1000 songs or instrumentals that will fit any situation?
Are your excellent, top-of-the range instruments always in tune, without messing about between songs?
Do you have a p.a system that really works?
Is your transport reliable?
Do you have a good reputation for reliablity?
Go figure and think this one out.
think about it......