Why do I need to use end-to-end tracking?
As a seller, you would agree that anything that cannot be tracked online is as good as lost. A missing item means that not only have you suffered a financial loss, but your reputation as a seller has been tarnished and the buyer has lost faith in making any future purchases from you.
The biggest drawback with shipping without a proper tracking service is that you will not have any proof that the item was actually shipped and/or was delivered within the listed timeframes.
Buyers typically are impatient when they are waiting for an order to be delivered. Once the given timeframe has lapsed, they will go ahead and open up an “Item Not Received” case” and at times will not even wait for a seller to revert. The case might then be escalated to eBay and when eBay intervenes, a black mark will be noted on your account. e.g. your account’s performance will be impacted.