Earlier today Paul Misener, the Amazon VP for public policy, testified in front of Congress. He wasn’t there to make an offer for Amazon to buy North Dakota (they need the warehouse space); that’s tomorrow. No, Paul was there to speak in favor of passing new laws to close the current loopholes in existing sales tax laws.
Most states require residents to pay a sales tax on all their purchases, but they also require a retailer to collect it. This has led to a rather tricky situation when the retailer is located in another state and thus has no obligation to collect the tax.