I'm a big guy, we all know this (assuming you have ever met me or seen a fairly recent picture of me). Sure, I'm not as big as I once was, but I'm a solid XXL when it comes to shirt size.
And speaking of shirts, one of my favorite shirt suppliers is Tommy Bahama (shocking, I know). Their XXL shirts fit me nicely (generally speaking) but it would seem that some people find the XXL too big, but the XL too small. The obvious solution is the XLX.
That's right, a size right between the two! I can't decide if this is genius or idiotcy, but I suppose if it sells a few more shirts Mr. Bahama is happy.