Merchandization is a critical term coined by the anti-globalization movement to designate the process of change in viewpoint of individuals or society towards an object, service or substance. Things that were formerly thought of as "simply being there", are now being thought of as commodities for sale and corporate profit. This change in viewpoint is called merchandization of an object.
Marx discussed this "fetishism of commodities" in the nineteenth century.
Political Economy has indeed analysed, however incompletely, value and its magnitude, and has discovered what lies beneath these forms. But it has never once asked the question why labour is represented by the value of its product and labour time by the magnitude of that value. These formulæ, which bear it stamped upon them in unmistakable letters that they belong to a state of society, in which the process of production has the mastery over man, instead of being controlled by him, such formulæ appear to the bourgeois intellect to be as much a self-evident necessity imposed by Nature as productive labour itself. Hence forms of social production that preceded the bourgeois form, are treated by the bourgeoisie in much the same way as the Fathers of the Church treated pre-Christian religions. . . . . Could commodities themselves speak, they would say: Our use value may be a thing that interests men. It is no part of us as objects. What, however, does belong to us as objects, is our value. Our natural intercourse as commodities proves it. In the eyes of each other we are nothing but exchange values.— Karl Marx, Das Kapital, volume one, part I.1.4
In other words, something may have usefulness, but it has no value unless it can be exchanged in the marketplace for something else considered to have value. That value may come because it fills a need through consumption or being further exchanged. In this way, labor, time, and natural resources have come to serve the market instead of the other way around.
The slogan of ATTAC is "the World is not Merchandise" (le monde n'est pas une marchandise).