Let's say you have various sources from which you could buy a particular large item, like a range hood that looks like this:
You decide to buy it from Amazon because of the ease of dealing with Amazon should something go amiss. The hood arrives, and gets installed, and then, the last step, after it's installed, is removal of the protective tape coating on the top of the horizontal piece. You cannot see it but your installer points out that there's a scratch. You contact Amazon, and you are given three choices: return and refund (obviously not feasible), return and replace (feasible), or a partial refund. You tell Amazon you will consider either of the latter two options. At the very least, you are likely to get a 20% partial refund on the purchase price. Given that no one ever will see the scratch, you could not be happier.