Low overhead, high efficiency
Since VPS is based on the operating system level, the cpu, memory and diskspace overhead for virtualizing is very small. One host with 2 GB of ram can easily run 600 instances, each running a standard FreeBSD installation plus sshd, without swapping.
Similarity of virtual to non-virtual environments
A virtual server looks und behaves as much as possible like a physical one, making it easy to convert physical servers to virtual ones.
VPS instances can be migrated from one physical host to another, preserving the running state. This includes all resources like network configuration, running processes and established TCP connections. Watch the live migration demo video.
Resource control and accounting
CPU utilization, number of threads and processes, virtual memory, physical memory, block I/O utilization and diskspace can be monitored and limited, making it safe to provide virtual servers to customers.