Not really - with Amazon you have to add shipping and a trip to the local post office (since they _never_ deliver when you are home), and nobody is going across town to save 20$ on a several houndred dollar widescreen tv.
But when you don't go to the store _at all_ there is no way they make a sale.
The cost of the TV shouldn't make any difference to your willingness to go across town to save $20. Saving $20 on something that costs $400 gets you exactly as much benefit as saving $20 on something that costs $40.
That's not to say that you should be going across town to save $20 on anything. It might well not be worth the cost in time and fuel. But doing that to get a $20 item free, or a $40 item at half price, shouldn't be any more appealing than doing it to get 2% off the price of a $1000 item.
(It's a serious bug in our wetware that all the above feels so unintuitive to most of us.)
Yeah but if you can afford several hundred dollars for a tv you aren't likely to be in the category of people who care about $20 bucks, whereas if you buy something for $40 you might.
But when you don't go to the store _at all_ there is no way they make a sale.