Shouldn't the event be just as much an effort on the writer's part as it is on yours? You can only do so much in getting people to come to your store. What in heck did he do to help promote his own book event?

I wouldn't be surprised if he did absolutely squat. If I were set up for an event, I'd be enlisting all my friends and my family and their friends and their families to help me get the word out (not to mention show up at the event).