Quite often you will begin tracking products that have an alert shown under them in Sales Spy that warns you that there are more than 1,000 units in stock. This simply means that this seller is holding more than 1,000 units in Amazon’s warehouse. When this happens, we are unable to track inventory so you will often see zero sales. This is because of the way the information is received by us from Amazon.
This does not mean that the item is not selling. On the contrary, it probably means it’s selling well! Why else would you hold more than 1,000 of it in stock?