eBay has a money-back guarantee, so if your item doesn't show up, then you come to eBay and we will make you whole. Then we will go and sort it out with the seller. This is why tracking is so important, so the seller is able to justify that they inducted their package, that it went through, and that it was or wasn't delivered. If there's an actual issue with something being lost in the mail, and you can prove that with tracking, then we would go to Canada Post. It rarely happens that things actually get lost. Usually you have a bad actor, so tracking allows you to sort that out very quickly. That's what usually ends up happening. The first line of interaction is the buyer and seller, and then eBay steps in the middle and will use the tracking data to sort things out.
On October 31st, 2016. See this statement in context.