Marx did believe as Heartfield notes that consumption, along with political activity, was a means to liberation. Marx refers to the consumption of reading material; O'Connor refers to the consumption of brands, such as Nike. I cannot believe that Marx would be particularly enthusiastic about the susceptibility to brands.
Marx's discussion about the positive use value of consumption came in the Grundrisse, as Doug's extract from Mandel suggested. In Capital, especially in the discussion of fetishism, Marx was following the approach that Jim O'Connor attributed to him: namely that markets were controlling people, rather than inverse.
So Marx applied it consumption, but not mindless consumption. Rather he called for consumption that would expand the mind, along with powers of the working-class.
I thought the most insightful part of O'Connor's message was the consumption was a mediated process, as his examples of reading books indicated.
-- Michael Perelman Economics Department California State University Chico, CA 95929
Tel. 530-898-5321 E-Mail michael at ecst.csuchico.edu