Originally Posted by kindlekitten
I thought it depended on the purchaser's state!?
It's all beyond the understanding of anyone without a degree in commercial law, and it depends on the specific laws in each state. As I understand it, in general, if the seller has any sort of "physical" presence in a state, then anything it sells to a consumer in that state must have sales tax applied. Apparently the major publishers have some sort of presence (or legally need to claim such or whatever -- beats me), so they charge sales tax in all or at least the vast majority of the states. In the case of this "agency model" stuff, the publisher is the retailer and Amazon is just the "agent" supplying the connection between consumer and seller.
On top of that, with most states (if not all), when you purchase something by catalog or on-line and do not pay sales tax for it, then you are supposed
to be reporting it and paying it on your local tax returns. Of course, most everybody ignores that (or is not even aware of it, though I think with some big-ticket items like autos, they have to be reported to your state if you buy it out-of-state where you are not charged any local sales tax.)