Spot Instances offer the greatest cost savings for workloads that can be interrupted and do not run continuously. They allow customers to bid on unused Amazon EC2 capacity and are ideal for workloads with flexible start and end times. On-Demand Instances would not be cost-effective for a non-continuous workload. Reserved Instances would require up-front payment or a commitment for one or three years, which may not be ideal for non-production workloads with flexible timing. Savings Plans also require a commitment and would not provide the same level of cost savings for an interruptible workload.