Welcome to Just Marketing

Have you ever heard anyone say "ah, but that’s just marketing."

Maybe you've even said it yourself.
“Just marketing”???   What does that phrase mean?
As I understand it, at best it is dismissive, a trivialization of marketing – as in, “it’s nothing important,” “nothing you should take seriously” – it’s just marketing.
At worst, it is synonymous for "it's a lie," or "they're just lying." As