If a shipment enters a region that is below freezing, it can definitely have a negative effect on the paint.  I had thousands of dollars of this very paint shipped to me, and it was frozen when it arrived.  Even after warming up, it was destroyed.  It turned into a jello - like substance and could not be remixed/shaken back.
 
	The other issue is shelf life.  You never know how long the re-seller has had the product in inventory.  If the product has a shelf life of 1 year, and it took 6 months to sell that particular bottle - the customer now has a product with a shelf life of 6 months, and they won't even realize it.