Because the prize was a pair of Oakley Jawbone sunglasses - the very model worn by almost every rider in the Tour de France (it seemed). But these are no ordinary Jawbones, these are the Transitions model, which feature photochromic lenses which darken according to the intensity of the sunlight.
In this country it more than likely means they will be clear for most of the time, but hey ho - my eyes love 'em.
In case you're wondering what I did to win them, I finished the sentence: "Eyewear Oakleys because ..." with the line "... when the crap hits your face at least you'll have some eyes left." The Sunglasses Shop evidently thought that was worthy of a win. I'm sure you have your own opinion.