I think the sales tax issue is a big one, but I'm not sure it's really that big.of a deciding factor for most consumers. I've been paying sales tax at Amazon forever (I'm in KY) and it hasn't discouraged me from using any of their services. I go with Amazon for the convenience and the fact that I can often find free shipping offers from them on many itmes, which more than offsets the amount of sales tax I have to pay.
That said, I could be entirely wrong. :) If I didn't live in a small town that was at least an hour away from all major retailers other than walmart, I might be using Amazon a lot less.
It would be interesting to see some statistics on their sales in states that pay sales tax vs. states that don't, provided they also took into account the overall spending patterns of the people in those states.
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.
Not to mention, Apple is not in the business of physical content distribution (i.e., mailing DVDs), and already has a very popular streaming product available.
They could definitely do with the user tracking and recommendations side of Netflix, but that alone doesn't justify a takeover.
