Like many such seedy, sinister institutions, it is housed behind a smart door, on a smart square, in a smart part of town. It is discreet.
Advertising is one way of relating to the public at large - H.G. Wells called it legitimised lying. Bill Hicks described everyone who works in advertising or marketing as 'the ruiners of all things good', and advised that they kill themselves - no joke.
As with tanks and television, the medium itself is not inherently evil: those that drive it, that set its agenda, mediate its morality. Indeed, communication(s) could be the crux of our existence as sentient beings. It can bring understanding and acceptance; it can transmit joy, hope and love.
But adverts never ask me to think about anything beyond my own selfish needs; the television only ever tries to persuade me to purchase, never to pursue peace.
The biggest PR coup of the 20th Century was to convince the individual that solidarity is pointless. Public relations told the individual that the individual alone was important. You can't change anything until you've changed yourself, it said. And, happily, it had a plethora of products on hand to help with self-improvement. No need to think too much (certainly not about other people, who are, after all, hell), just reach into your pocket, sign on the dotted line.
Nobody deals with this line of inquiry better than Adam Curtis in his documentary Century of the Self. Watch it, and remember: don't reach into your pocket, reach into you soul...