Let me start off by saying that I'm a big fan of John Carpenter's "They Live" - it's a great commentary on corporate manipulation of the public, and there's a fantastic 3 minutes of 2 guys hitting each other in the nuts repeatedly. The trope of a select few who unmask a massive conspiracy to control the public is a hollywood cliche, for the simple reason that it provides an awesomely dramatic narrative - everything is not what it seems, vast and powerful forces are arrayed against the heroes, who must do everything they can to stop the sinister conspiracy.
If you drop a piece of meat near an ant-hill and watch for awhile, a few individuals will eventually stumble into it, and gradually others will join them, until there's a large enough group to scavenge the meat, either cutting off pieces or dragging the whole thing back to the nest. It would be possible to imagine that this is a directed activity, that there's some kind of central decision-making process that determines that X number of ants will be required, and they're assigned the task. But in reality, it's an aggregate of decisions and actions by individuals that solves the problem. There is some communication, but it's very basic. The individuals follow a simple set of rules (eg: 1.Wander. 2. Find food. 3. Bring back to nest.) that accumulate into a correct solution, all without any kind of central decision-making. This is called swarm theory.
As things stand now, we as individuals are that piece of meat, from the perspective of the corporate and non-corporate entities that surround us. We are a resource. We buy things, we watch things that make us want to buy things, we participate in activities, we vote, and so on. I argue that the core currency of the economy isn't money, it's attention/presence. If we give our attention to a job for 8 hours a day, that provides value to the employer. If we watch tv for 2 hours a day, that provides value to the media. If we go to church, if we read the paper, if we take our kids to soccer practice, we are committing our attention to a larger entity in a way that provides value to that entity.
Naturally, those entities would like to retain our attention, up to a certain cost. If we leave a job where we're providing value, there's a replacement cost. If we change channels, or turn the tv off, or change churches, or start reading a different paper, or switch our kids to hockey, we remove our attention from a particular entity, resulting in a loss of value/resources for that entity. So they're motivated to try to maintain our attention, up to a certain cost.
So looking at this from a media perspective, various media entities are competing for our attention. We're living in a time with hundreds of channels, and near-infinite availability of media on the internet. There is no pre-modern equivalent to this kind of media availability in human experience - for most of our evolution, we spent most of our time in small tribes of 30-50 individuals. We do not have effective filters for dealing with the fascinating cacophony of information and entertainment that is available to us, but are still drawn to the same things that have always interested humans - sex, drama, justice, danger, opportunities, conflict, and the weather (I may be missing a few things here).
The various media entities compete to catch and retain our attention. They devote vast resources to doing so, and those that are effective can afford to spend more to keep doing so. That's what they want to do - they want to get that piece of meat and drag it into their nest so they can raise more ants so that they can get more meat to drag into their nest. That's it - it's pretty simple.
The vast corporate propaganda conspiracy theory is appealing on a certain level, because it provides a relatively simple answer to the profound gap between the problems that face us (eg environmental disaster, profound social injustice) and what is being done about it (not enough). It's somewhat reassuring to imagine that there is some nefarious cabal that can be targeted and destroyed/disempowered, freeing humanity to live peacefully and prosperously.
But the truth is, this is what we've chosen. We buy stuff made in China because it's cheaper, we stay home and watch Lost for the weekend instead of protesting because it's more fun, we keep eating meat instead of going vegetarian because we like steak, we keep driving cars and using a/c because it's more comfortable, and so on. If we cared enough about anything we could go Gandhi and get rid of all our stuff and devote our lives to that, but almost all of us don't, because we're pretty comfortable where we are.
There's no need for a vast corporate propaganda conspiracy theory to explain why things are the way they are - it's simply a highly effective consumption-based culture. Individual entities compete for our attention, and the effective ones get more resources, enabling them to compete more effectively for our attention.
One of the ways to compete for attention is to tell people that there is a vast corporate propaganda conspiracy. That has been very effective on both a fictional level (eg They Live, The Matrix, et al...), and on a real level. It is a core theme within the Tea Party and the far right, complaining about the liberal media's conspiracy to degrade and destroy America.
It isn't hard to string some facts and data points together to put together a vast corporate propaganda conspiracy theory, since as the public, we're lied to all the time. Beer is branded as ice-cold, when actually that's an external property (requiring a refrigerator), not an intrinsic one. Various government and corporate entities have lied, misrepresented reality, and hidden truths from the public since forever. And there have been collusions and conspiracies between and within government and corporate entities since forever.
But stringing facts and data points together to claim a vast corporate propaganda conspiracy is enormously problematic because it precludes critical analysis and individual agency. It rejects the ability to discern between good actors/actions and bad actors/actions because everything is corrupted by the nefarious cabal behind the vast corporate propaganda conspiracy. Individual actions like buying local and reducing consumption are virtually pointless, as is voting and participating in local politics, because we're powerless against the vast corporate propaganda conspiracy until we unite and slay the giant evil spider that is destroying the world. Syria's just like Iraq, because they're both wars, and government people say that we should do something, and they're talking about it on tv a lot.
Well, here's my conspiracy theory, from RFK:
Few will have the greatness to bend history itself, but each of us can work to change a small portion of events. It is from numberless diverse acts of courage and belief that human history is shaped. Each time a man stands up for an ideal, or acts to improve the lot of others, or strikes out against injustice, he sends forth a tiny ripple of hope, and crossing each other from a million different centers of energy and daring those ripples build a current which can sweep down the mightiest walls of oppression and resistance.