The theory goes like this: capitalism combines with consumerism and advertising to make us sad, lonely, and forever chasing after material goods. So we consume endlessly and the Machiavellian capitalists reap the rewards. It's not a great theory. 

Other psychic factors being equal, it is to everyone's self-interest to maximize his monetary income on the market. But this maximum income can then be used for either “selfish” or for “altruistic” ends.