Well there are bands that go out and play shows for much less. Yes I understand U2 is huge, I understand it is all about business and not music, regardless of what most want to believe..
SO!!! Knowing the types of fans this band has had for decades and thinking about how many shows the average fan goes to and the fact that you are charging them 50 for membership in a 'fan club' that is really just early access to ticket allotments. WHY NOT just change the rules, we get it, you want more $$ so why not just say you can buy 2 tickets to, up to 3 shows (probably the average person here goes t