https://phys.org/news/2018-06-online-sellers-comply-sales-tax.html

The ruling has angered many small online retailers and advocates for small companies because it will increase their expenses, mostly from the cost of software and services to help sellers collect the taxes and send the money to state authorities. But brick-and-mortar retailers who have had to collect tax simply because they have a store, office or warehouse in a state say the court has leveled the playing field, as online retailers will no longer have an advantage created by tax-free shopping.

The decision overturned two decades-old Supreme Court decisions that allowed companies without a physical presence in a state to avoid collecting sales tax. The internet has changed retailing, and Justice Anthony Kennedy, who wrote the new decision, said, "each year, the physical presence rule becomes further removed from economic reality." Kennedy also noted the existence of software that "may make it easier for small businesses to cope" with compliance.