Final answer:
Customers choose Preemptible VMs primarily for cost savings, using them for non-time-sensitive tasks that allow for interrupted operations without the loss of critical performance.
Step-by-step explanation:
The main reason customers choose Preemptible VMs is cost savings. These types of virtual machines (VMs) are offered by cloud providers at a significantly reduced rate because they can be terminated at any moment if the provider needs the resources for other tasks. Companies often utilize Preemptible VMs for flexible workloads or compute-intensive tasks that are not time-sensitive, such as batch processing or data analysis, thereby achieving considerable cost efficiency without a compromise on performance when the system resources are available.