Random thought, I wonder if US radio is having a problem because it has no frame of reference for a pop group that is only getting bigger at the 5 year mark. All of our groups are always way past peak or broken up by this point, because they've either been primarily a tween image marketing exercise or a vehicle for grooming a young solo star. The UK, by contrast, has seen Girls Aloud release their biggest album after the 5 year mark.