I have recently purchased large area rugs from several sellers on ebay.  I had not thought to ask HOW the rugs would be packed for shipping....until one arrived, rolled (as expected), then FOLDED in half and stuffed tightly into a box.  It was so seriously warped, I had to resort to hiring a professional, who steamed it at a very high heat, then placed heavy presses on it while it dried. 

Now I ask the sellers how they pack to ship, prior to bidding.  Never invest in a rug without first asking this question!