That would have been worth mentioning in a piece discussing a new organization dedicated to reining in Amazon. Through much of its existence Amazon did not collect sales tax in most states.
As this became more contentious and it had a physical presence in more states, Amazon eventually agreed to start collecting sales taxes in all states. However, it still does not collect sales taxes on the sales of its affiliates, who account for more than 40 percent of the sales through Amazon's site.
This is a massive subsidy with literally no policy rationale. In effect, the government is subsidizing purchases through Amazon at the expense of brick and mortar stores, many of which are small businesses. This policy is costing state and local governments billions of dollars in revenue and helping Amazon to grow at the expense of its competitors.