The Convention on Contracts for International Sale of Goods (CISG) was supposed to increase legal certainty and reduce the transaction costs of international buyers and sellers. This Article argues that none of these goals has been met. A survey of 181 court decisions and arbitral awards applying the CISG shows that the vast majority of international buyers and sellers do not address the issue of the law governing their contracts, irrespective of the value at stake. Although the data is not easy to interpret, it follows that international buyers and sellers are simply not concerned with the legal regime governing their contracts and may be more generally legally unsophisticated. As a consequence, increasing legal certainty does not benefit them ex ante, and they do not incur the transaction costs that a harmonization of the law of sales could save. It is true that a few of these parties do provide for the applicable law and seem to be more sophisticated. But this Article further argues that even these parties do not clearly benefit from the international harmonization of the applicable law because of its limited scope.