The basics of marketing work online and off. We see things the "gurus" do and complain about their sneaky tactics. We can't understand why they do what they do so we threaten to leave their list or whatever.
But when we see real examples of the principles practiced by real companies with real stores and real employees, maybe it will help us better understand. McDonald's uses the scaricity tactic with the McRib.
Sometimes you have to look between the lines too. For example lots of people complain about testimonials because they are fake or the author's buddy or promoting something together or had the same 3rd grade teacher. Real companies don't use "scam" tactics such as that some say.
Ever considered what Amazon reviews are? They are testimonials.
The list is dead and email marketing is only used to scam people out of thier money when a guru does it. But when Microsoft or Paypal or the local bank or Barnes & Noble or Domino's Pizza does it, it's on the up and up.
It's not fair if a guru lowers a price as part of a promotion. Some even have the audacity to get a refund or do a chargeback so they can buy at the lower price. We cry "foul" when this happens. Why not try that the next time the BK Whopper or Diet Cokes or toilet paper is on sale and then goes back to its original price?
There's more to online marketing and business than you see here in this forum. Open your eyes and you can learn a lot about how it all really works.