The Edmonton Journal's Misty Harris examines the phenomenon of anonymous/pseudonymous supposed-celebrity bloggers such as Rance, asking pointy-headed types like a sociologist, a pop-culture-expert college professor, and a "noted expert of celebrity fandom" why the famous might want to engage in stealth-blogging. Predictably, they come up with the sort of goatee-stroking jibber-jabber we'd expect to hear from such experts: they want to project characters and court intimacy with fans, and so on.
We think it's pretty obvious why celebrities author pseudonymous blogs. For the same reason that they move to Hollywood, stage meals where they can be photographed with people they're not really dating, and talk loudly in their unmistakable actor-voices while they're blowing rails in the bathroom of the Standard: because coke gets you nice and fucked up. Oh, and also for attention.