[TChris]

The "e-tailer" does not pay the tax. The purchaser who lives in the state pays the tax.

Right, but they would pay the tax on purchases originating outside the state, right?

Interstate sales have always been off-limits for taxation, haven't they?

Legislation such as this turns the e-tailer, or Amazon, into a tax-collection agency, and puts them under the jurisdiction of the State of Colorado, to one degree or another. See the problem?

[Peet]

I said: The "e-tailer" does not pay the tax. The purchaser who lives in the state pays the tax.

Right, but they would pay the tax on purchases originating outside the state, right?

No. The retailer is supposed to collect the tax for the buyer's location. This is, of course, ridiculous because state, county, city, etc sales taxes are all over the place. Vendors would need hugely complex systems to comply.

Interstate sales have always been off-limits for taxation, haven't they?

Not in my state. For example, we pay sales tax on most purchases from e-tailers who also have a brick-and-mortar presence in-state. We are expected (by law) to pay sales taxes on all other out-of-state purchases, (internet, or B&M) though I suspect not many do. The state just went after a tire retailer in a neighboring state trying them to collect our state's sales tax on tire purches made in their state. They failed.

Other states' laws may be different...