There is an article and interview in the uni's newspaper:
Q. So how did you come to be on the Campus Invasion Tour?A. I guess we just wanted to do another tour around the springtime in the states. We've got it finished everywhere else in Europe. Our album came out six months behind in America, so we just wanted to fit in another tour before we start recording the next album. Just squeeze one in. So somehow, it came about, and we said, "Yes."