Witness the photo at right. The seat sticking up is a 68cm bike,  which has been sitting outside my local bike shop for three-plus weeks. This is Exhibit A of why stores dont sell tall products: because the chances of a super tall person walking by and needing a super tall bike at that very moment are slim.

Every time I walk by, I pet its handles  and tell it not to worry, because some 6'8"er will come by soon and take it home and love it very much. And I tell the store owner that it's pivotal that he always keep one in stock, because he'll sell one every month, and that's twelve bikes he wouldnt sell otherwise.

And then it finally happened. Yesterday, someone bought him. He was 6'7". New tall bike forthcoming.