Use Case: New item promotion, upsell for specific item.
From the sample above, there are 2 rows of items added into the rules item list. This means that the promotion will be triggered when any 2 items are added into the sales.
With the promotion process sequence, the system will get the cheapest item and run the effect from top to bottom, which means it will run Discount by 100% for cheapest item and the second cheapest item with 0% discount.
The priority is 10, which means it will overwrite the priority lower than 10 and will be overwritten by rules with priority higher than 10.