evidence: When country superstar Garth Brooks puts on a show, it typically sells out. Seats almost always sell in the secondary market for thousands. Last night, the singer learned that vilifying your own fan base and calling them a-holes is a costly endeavor. [...] "It was embarrassing," said tour manager Joe Barron, "Poor Garth was waving people from the nosebleed seats to come down front. None of the floor seats sold. It was sad."