I always wondered why a battery company thought I'd buy their batteries because Michael Jordan said they were good. I mean, he played great basketball for sure, but how in the world did that make him an authority on batteries?
And, honestly, with all Tiger's money, did I really believe he actually drove a Buick? And that, if he says so, I oughta go ahead and buy one myself?
The concept of the celebrity endorsement depends on a socio-psychological reaction to a perceived person of power or authority. Note that "power" and "authority" are not the same: in the cases above, there's no logical connection between the athletes and their knowledge or expertise in batteries or cars - it's not their authority that influences us, it's our perception of their power to which we're more willing to acquiesce.
