Older sister gave me achtung baby when i was 10, a fan ever since, 31 now. Not sure about an average age for a u2 fan, maybe the rate at which new fans are gained and old ones stop being a fan / pass away is another interesting question? Obviously the peak at which new fans are gained has long gone and slows down with each album release. And are older fans starting to no longer be a fan? Are theymaking net gains or net losses?.... Depends how you define a fan haha! Which is the horrible, thorny question that causes upset, argument, judgemental comments etc.... Best leave it then haha....