The reality is, Simpletire does not own any tires. They are a marketing company that has access to other people's inventory.
They are uploaded inventory from each company that owns tires each day and they sell from that stock. Your order can be coming from anywhere from a large distributor, or even a mom and pop shop. You just don't know. The reason so many orders get cancelled is this; When you come into your tire store each day and have a chance to sell a tire that Simple has ordered for a much higher price, then you cancel the Simple order.
Just that simple. This is why so many orders get cancelled for buyers when they place orders with Simpletire.