Hmmm, good idea, but think about the number of non-etsians who dont know about the law yet & will continue to buy from these big stores, Im afraid that the, in reality, small number of us who would do that, wouldnt make a noticable enough dent to make that much of an impact in the grand scheme of things.
Sorry to be a kill joy, but there are just too many of them & not enough of us :(