Before you play any concert with a rock band, it tells you the probability the rock band will retire after the concert, but not the probability it will be promoted. The latter bit of information seems like it would be extraordinarily useful for planning your rock band strategy. Without it, you don't really know how uses a given rock band has in it in expectation, nor can you calculate the probability that a given rock band will live to see a second promotion. The "second promotion" issue is especially crucial when using rock bands for non-tourism reasons, i.e. loyalty attacks (Indie), gold (Pop Star) or conversion (Religious Rock). So has anyone worked out the relevant probabilities?