Get Notified when customer clicks "Notify me when product is back in stock"

I am trying to figure out how I can get notified when a customer clicks on the “Notify me when the product is back in stock” check box? I would like to know when the customer selects this box and for what product. We custom machine parts for our customers and it would make it much easier to know what product to make next from this check box. Right now we have to go thru all the products and see if there are any subscribers to that product. It gets very tedious when you have over 100 products. It would be nice to either get notified when someone subscribes to one of the products or find a place where I can see all the products and subscribers.

There might be a place to find this information, I am just not familiar with it. Any help would be greatly appreciated.

Please check Products → Products → gear icon → Product subscriptions