[ghaff]

Unless you're Amazon, which has yielded to pressure to collect sales tax in some states where it does not have a physical presence.

Note "collect sales tax." In at least some states, e.g. Massachusetts, residents and (I assume) businesses are asked on their state tax returns to report out-of-state purchases consumed within the state on which they are then responsible for use taxes equivalent to sales taxes.

[tsotha]

Amazon "yielded" to that pressure because they intend to have same-day delivery in every state. There's no way to do that without a presence in every state. So Amazon was going to be paying sales taxes anyway.

Since they've decided to pursue a business strategy that has them paying sales taxes, they're pushing for an agreement that has competitors paying taxes even without a presence in that particular state.