I bought my TV from a CA retailer, and I don’t live in CA. If he had been required to collect tax from me at that moment I would not have bought it.
Shortsighted law.
Sales tax is not even the driving factor in the success of internet stores over “brick and mortar.” If prices were the same, ordering off the internet would not be as attractive, since you have to add in shipping to the cost in most cases. The real advantage is the internet retailer not having to pay the same costs as the guy with a "real" store. Distribution costs are less when the inventory is centralized. Rent, electricity, etc. cost much less per item and there's lower cost of labor and regulation out of state. Add in volume discounts that huge buyers like Amazon have over smaller stores and the bottom line is that a $40 item purchased down the street may only cost $25 or so online. The tax versus shipping costs are a wash, but you still save $15 bucks either way.