If you find yourself lamenting the shallow pursuit of shiny beads, status symbols, whiz-bang toys, or the marketing thereof, your philosophical foe is nihilism.
If you find yourself lamenting the devaluing of individual differences, the callous marginalization of selves or others, or the realpolitik of global currencies and killings, your philosophical foe is nihilism.
In a world where nothing exists except perception, then nothing exists except perception, and the only possible rational course is to seek as many good perceptions as possible. In a world where nothing endures, then nothing endures, and the only possible rational course is to seek as many good fleeting things as possible.
No amount of supposed uniqueness in your perception of choice; of rarity or refinement therein, can save you. Your awareness of futility, while gorging on different flavors of bread or laughing to bloody tears before different circuses, does not make your bread or circuses any more worthwhile than anyone else's. In a world where nothing has meaning, we must all become gobbling, cackling fools, and all the better for it. Runoff from the local BP plant; water from the drinking fountain at Utama shopping center; store-brand soda in Minnesota; fluoridated and chlorinated tapwater in the Upper West Side; organic cabernet by candlelight: there is no difference, if nothing means anything. An outlook of nihilism that celebrates the educated experiences of the cosmopolitan individual trimming her organic backyard garden while listening to Eluvium and drinking free-trade coffee from the locally owned bookstore is weighted no more than an outlook of nihilism that celebrates beating your wife unconscious, having 11 cans of postdated beer, and watching old recordings of big trucks crashing into each other over the sound of 1980s British metal. If it's all bouncing billiard balls, there is no difference.
Consumerism is nihilism, and nihilism has already won this debate. If you believe that there is no deeper meaning to the world than the extent of your own feelings, then you must respect Jebediah's feelings that boozing it up on the couch is among the greatest of pastimes. Or, don't--because it doesn't matter. You're right that Jebediah is a fool deceived by his own naturalistic urges, and Jebediah is right that you are an over edumacated fool afraid to loosen your belt and really relax, and High Arka is right that something is wrong with this equation, and it doesn't matter anyway because no one is, or can ever be, right.
Why do we get embarrassed when otherwise-sensible people begin to talk about feelings and deeper meanings? Because we have been trained that there are none. The philosophical underpinnings of mass perspective that allow things like consumerism and imperial war to exist are those of nihilism, because if there is no deeper meaning, then this all doesn't matter.
A trap awaits the more intelligent in this system. When you have realized that the world is filled with a bunch of people hurting and killing and gobbling, you may use this as evidence that there is no deeper meaning, and thereby join them in your own version of their hollow pursuits. It's futile, so let's eat cake. All roads of nihilism lead back to nihilism, though. When you accept that there is no deeper meaning, you lose any grounds from which to make your critique: not only of wife-beating and beer-drinking, but of anything at all.
Moreover, the evidence which leads you to conclude that the world has no meaning is self-justifying. The morass of human waste and pain that justifies nihilism is caused by nihilism. A thousand quiet little shrugs that it doesn't really matter, anyway, slay the conscience and encourage upgrading to the premium package on your new crew cab pickup truck. Why not? Why not have an eentsy weentsy bit more fun before you vanish?
Our most basic perceptions of why and how we exist are fundamental to creating the minute details of this place. We got here randomly. Stuff happened, so here we are. Life's short, so play hard. Stuff happened, and then this other stuff happened--just 'cause, man; just 'cause, man--and since of 'cause that other stuff there was this stuff and then, like, me, man. Totally deep.
In the temporary prison of nothingness, what does it matter what you grab and who you shiv? Even if it does, it doesn't, because you've already concluded that there is nothing.