This addon will show how many customers have signed up for individual product notifications. The data shows in the side column when looking at a product in the admin/catalog.php structure.

If the product has subscribers, you can click to show the subscribers name and email address.

There are NO CORE CODE CHANGES in this addon.

If the price of this addon does not suit your business, contact me anyway. I'm sure we can come up with a good deal that suits each other. Prices are not set in stone.