Has a Celebrity Ever Convinced You to Buy Something?

We see ads on television all the time for different products.  For example, comedian Jerry Seinfeld was hired to draw attention to Microsoft and the Windows operating system (even though there was always a Mac on the set of Seinfeld).  Sports stars promote shoes, energy drinks, and the like.  What I'm curious to know is whether this advertising actually works.  Have you ever bought something primarily on the basis of a celebrity endorsement?  If so, what did you buy and what was it about that endorsement that made you consider the purchase?