Advertising has fascinated me since I studied psychology and sociology in the 70s, especially the areas of behavioural impact of perception, psychological programming and psychological reactance.
Subliminal advertising was the first, but now widely illegal form of advertising (less illegal in the USA where it still crops up from time to time) that made me aware of how to manipulate audiences. Audiences are flashed messages for about 0.003 seconds on e.g. a TV or cinema screen that we can't pick up in our conscious mind but are picked up by our deeper subconscious mind which is why back in the fifties cinema audiences were all desperate to buy a burger, an ice cream or a drink without suspecting they'd been programmed to do it. Obviously they just assumed it was a natural desire.
Nowadays, advertising is regulated in most countries a number of areas including false advertising i.e. making false claims about a product which is actually untrue, puffery (not illegal to claim that you e.g. make a better pizza than the competition as it's subjective) editing photos of e.g. people in weight loss adverts to make them look thinner than they are in reality, omitting key information, hidden fees/costs, oversize packaging, misleading health claims, failure to point out risk etc etc but there are still huge problems that need to be addressed.
Two main issues for me are 1) that prosecutions for lying in advertising are few and far between. Usually the people behind them are so rich and powerful (Murdoch for example) that prosecution is simply not affordable and 2) that in the absence of prosecution or penalty advertisers are increasingly publishing/screening outright lies as fact and as their worst possible outcome is being told to remove the ads they still win because the damage has been done and can't be undone.
I banged on about this in the B-word thread so I won't revisit that but given that advertisers now have greater consumer reach, greater ability to "push" adverts and more information about consumers than ever before in history thanks to the internet and especially social media I really hope that society can somehow find a way - and the balls - to get a grip of advertising before our ideas, opinions and lifestyles are completely controlled by the global corporations who employ these techniques to the greatest effect and nowadays to sell a lot more than products and services.
The problem is rooted in ourselves though due to psychological reactance. Reactance is the fear of having our behavioural freedoms limited or curtailed by external forces - effectively removing our freedom of choice - so in a way society tends to tolerate more than it should having our opinions and behaviours manipulated by others because fundamentally, nobody likes to admit they were manipulated even if they recognise it has happened.
And the entire raison d'etre of advertising is to do just that - manipulate us, ideally without us even knowing it has happened.