When you have assigned supercash for the products (from products tab), the customer purchasing those particular product will be eligible for supercash and the same is reflected here. 

For example if you have you assigned as follows

Product A  – 2$

Product B – 5$

Product C – 0$

Product D – 0$

So when a customer places an order for Product A, Product B and Product D, the sum of eligible supercash which is 7$ here in this case, will be reflected here in this page. As an admin you need to click the credit button for that particular order so that customer will recieve the SuperCash. Notification is sent to customer if enabled.