Labels create band demand. Concert promoters do not. I promise you this is causation and not correlation. People go see shows because they have the record and know the band. I am sure you have never gone (willingly) to see a show from a band whose music you didnt already have and/or or know pretty well. The band marketing (the label) created the market environment for you to know and like their music. People do not go see artists because they saw some add in a local paper advertising an artist. It doesnt happen. Promoters only provide awareness so that if you are a fan you will know that this band you like is in town.