Sometimes a search finds an item that is out of stock on Amazon. That's great news for you, isn't it? Order the product and get yourself exclusively into Amazon's Buy Box?
It can also be that you've come across a duplicate of the product in Amazons catalog, presenting itself as an out of stock ASIN, while a fully stocked identical product exists under another ASIN.
It's important to see if you've uncovered a gem or a dud. Doing a title search on the Amazon search page is one easy way. Perhaps you'll find the same product under a slightly different name.
Or you may discover that it is in fact an ASIN with a good sales history, recently out of stock, and just waiting for you to send in a shipment.
We suggest this configuration for most users who want to explore these potential opportunitues:
Toggle ON the first switch to include Amazon out of stock items.
Toggle OFF the second switch. This is for specialized searches.