Amazon's ways of getting help are... confusing... at best. Recently I ordered something, shipper marked it as delivered, but it wasn't there. I dug through the orders interface, trying to find an option for "item never arrived", but could only find things about returns and exchanges, or ways to report damaged items or bad packaging. After searching the customer support site for the problem, the (non-interactive) answer was essentially "wait 48 hours because sometimes things appear later than indicated". It had already been more than that, and there were no follow-up steps beyond that.

Eventually I googled the problem, and got linked to some random non-Amazon site, that told me to go find the generic "Help" link, and dig through a couple screens until I found a link to a chat interface (basically a "nothing here is helping me" link), where a robot would help me. The process worked perfectly and easily once I got there, but there's no way I would have gotten there on my own.

I suspect some people, when confronted with a missing item, will try part of what I did and just give up and eat the cost, especially if it's a cheap item. So the internal metrics look good, but that's not telling the whole story.