Celebrity books - in the decline phase of their product life cycle?

The CEO of Waterstones has fallen on his sword after disappointing Christmas 2009 sales. But I hope the bigger story is the evidence that we might be finally coming towards the end of our obsession with talentless celebrities. The retail book trade (which now includes the grocery supermarkets) has been sustained with volume after volume of celebrity memoirs for several years (topped up with some Harry Potter). But the Waterstones sales performance suggests that UK consumers are tiring of reading about the same old celebrities. Add that evidence to the decline of Big Brother, falling attendances at live shows like SCD & DOI - is celebrity media finally onto the decline phase of the life cycle?