I used to work for an online retailer.  Sales taxus so much worse with the internet.  The point of sale is where the customer customeris when they click buy, and the business had to collect report and remit the correct sales tax to the correct jurisdiction.

We were a small business with two people in accounting, and we spent about half our time trying to figure out the sales tax for many jurisdictions across the US.  We had to file every month in a bunch of states, but also a bunch of countries and even a few cities that collect their own sales tax.  They each had their own unique set of rules.

I think sales tax probably made the most sense of and tax before the internet, but it is madness now.