Amazon strategically places its warehouses just outside of the most populated states. Imposing sales tax would be mean they immediately lose a ~10% pricing margin on sales to states like California. That's quite a big impact.
If you look carefully at the way prices are set on some of Amazon's items, they actually set the price at just below the list price + sales tax for some populated state, such as California. So at first glance the price will seem to be higher than a competitor's, but it's actually cheaper since the competitor (i.e. a b&m retailer like Wal-Mart) has to charge sales tax.
If you look carefully at the way prices are set on some of Amazon's items, they actually set the price at just below the list price + sales tax for some populated state, such as California. So at first glance the price will seem to be higher than a competitor's, but it's actually cheaper since the competitor (i.e. a b&m retailer like Wal-Mart) has to charge sales tax.