I ordered a book and since the sender had used the prepaid postage, I've been able to track it.  It was half way to me when it took a turn and is now headed back to the sender.  The sender has already gotten their credit for sending but what if the book doesn't come back to me?  

I't not like a tracking number from the USPS where you can see the tracking history.  

Sometimes packages do a loop de loop and still get to the proper destination. Probably happens more than we realize since so much of the sorting system is automated. At least it's still getting scanned so it's accounted for.

BTW, if they did use PBS postage then the order details do have the USPS tracking number on the popup.  You can copy/paste number that to USPS to get more comprehensive (and up-to-date) tracking results.

Thank you!  I had never noticed the tracking number listed there before.  I input on the USPS site and didn't get anymore info but I did sign up for tracking info on the package. 

A book I sent once was returned to me. It was headed to Maine and got turned around in Virginia. I'm not sure why it was returned to me as it wasn't damaged or anything and was properly addressed. I had to take it to the post office to get it sent back out.

If you don't get the book, it will time out and your credit returned.