The essence of propaganda is to weave a story and engage the target population in an action that creates commitment to the story and creates secondary effect due to social proof as people see other people committing.
This is the essence of modern marketing as well.
Cancer is not really a well thought out way to describe it, it sounds a bit fanatical.
There is nothing conspiracy like about this. This is all well known and researched.
General public is just kept ignorant of it. I don't know why. Maybe it's because the more you know about how propaganda works the less effective it is? Thus teaching people en mass how propaganda works would make even benevolent attempts at mass mind control less effective.
[0] Branding is nothing new. In the viking age particular german swords were very well thought off - and they had particular inscription on the blade. The brand was so strong that blacksmiths around baltic created "pirate" copies of the blades by writing the same inscription - or, as some were illeterate, attempted to copy the markings resulting in almost-but-not quite correct spellings. As their clients were likely illiterate as well I don't think it mattered for business.