It has certainly evolved with the career of being an “influencer”. It’s certainly understanding how the culture & technological advances affect trends.
So what is persuasion? I’ll give you some examples which have been experimented scientifically.
It really depends on the geographic culture on how you act to the subject. That can be in what manner you speak to them (pronouncing particular things in a certain way) or the content of conversation or everything down to manners.
A way to influence is to tap into the fear of loss. That can be something like “we only have 2 left” or “a woman across the country is wanting more than you” -competition- or wanting what you can’t have -scarcity- sale price or sell by date.
There’s forms of influence, like if someone gives you a gift, you feel like you owe them something in return where it’s a gift, a favour or an invitation. We dismiss or have nasty names for those who don’t show obligation, like “mooches”.
It’s not what we receive, it’s that we re.
In financial terms, most of the things we are persuaded to do (or buy particularly) is not about the monetary value of the item. It’s about how awful, psychologically, to dismiss it.