Over the past decade, Amazon made a transition. Early on, they did not have a physical presence in your state. So when you purchased something, you purchased it sans sales tax. Retail brands howled how unfair this was.
Today, Amazon has a physical presence in many states. Much of what you buy from Amazon is subject to sales tax. Retail brands still howl about how unfair it is that Amazon (and you) do not have to collect sales tax.
Have you ever noticed that Amazon grows, virtually unfettered, regardless whether they collect sales tax or not?
Sales tax is one of those topics designed to generate page views. It's virtually irrelevant to your business. If you sell something that the customer wants, sales tax is a minor inconvenience.
The problem happens when we are selling stuff that the customer doesn't care about ... at that point, discounts / promotions / sales tax become important.
So maybe instead of focusing on sales tax we focus on what matters ... and what matters is what we sell.