Yesterday, while buying a new pair of shoes, I noticed something interesting. The wide size was comfortable on my left foot, tight on the right. The extra wide was comfortable on the right, loose on the left.
According to the seller, that is a common, perhaps even normal, pattern—the right foot tends to be just a tiny bit bigger than the left. My wife confirmed the pattern from her own experience.
My first thought was that perhaps a high end brand could take advantage of the pattern by selling shoes individually—one to fit the left foot, one to fit the right—instead of in pairs. It then occurred to me that the mass market approach would be to routinely make the right shoe of each pair a fraction of a size larger than the left. The first firm that did that ought to increase its sales, since lots of people would find its shoes a little more comfortable than the shoes of its competitors.
At which point it occurred to me that perhaps it was already happening. Does anyone know? Are right shoes and left shoes precise mirror images of each other, as I assumed, or do some firms routinely make one just a tiny bit bigger than the other?