Points
They add up based on what the customer spends. Good for rewarding bigger tickets.
With points, each purchase adds an amount you decide. The customer sees their balance on the card and knows how far they are from their next reward.
Each reward has its price in points. A customer with enough balance can redeem it at the counter, and the balance is deducted on confirmation.
At the counter there is nothing to work out: you type the purchase amount and the screen tells you how many points it adds before you press.