A "consumer culture" is one whose economy is defined by the buying and spending of consumers. Consumer culture is closely to tied capitalism, because it is driven by money. What distinguishes it, though, is that it is not focused so much on the power of money as it is on the happiness that can be attained through buying and owning personal property.
The United States is the most obvious example of a consumer culture, but ancient Egypt and ancient Rome could also be considered consumerist societies. Consumerism is usually identified with wealthy countries. When the Industrial Revolution made mass consumption possible, consumerism came to be seen as an effective political option to sustain a healthy, balanced economy.
A consumer culture can be viewed both positively and negatively. Proponents say that people are happier and more productive when their wants and needs are met, and that buying and owning things is a means to that end. The opposing viewpoint is that consumerism is wasteful and greedy and encourages consumption for its own sake. Both sides agree that consumerism is a sign of economic freedom. Much of the way we define the "American Dream" is directly tied to America's consumer culture.
When a country's economy is strong, consumer culture thrives. Purchases lead to more purchases, as supply and demand play themselves out naturally. Consumerism also dictates that it is not the producers of goods who determine what a society should consume, but rather the free-thinking consumers. That is to say, a product will not exist if no consumers are interested in buying it. In this sense, the economy is self-regulating and self-sustaining.
Critics say consumerism is shallow and drives people not just to meet their needs but to acquire status symbols, expensive things whose primary purpose is to demonstrate the owner's ability to purchase them. Instead of fulfilling spiritual or aesthetic desires, these arguments go, a consumer culture pursues external riches. Critics also say consumerism exacerbates class divisions.
Consumerism is often closely tied to materialism, particularly by its critics. Materialism is a philosophy that puts the importance of physical objects before the spiritual. When societies care less about their internal well-being than their personal possessions, the result is almost always materialism.