Advertising is a lie partly to keep you ignorant,partly to keep your revulsion at bay,and partly to assuage your guilt should you happen to come across the truth.
Take for example something innocuous and ubiquitous as milk.
On the milk carton, you might see smiling cows, green serene meadows, and words implying purity, freshness and vitality.
Reality is nothing close.
Google it if you want to know.