"PaaS can offer significant agility in your ability to launch and manage new applications. Even if you're under good configuration management within your IaaS fleet, PaaS is likely to deliver you a runtime environment in a fraction of the time", <a href="http://www.cloudways.com/en/" rel="nofollow">http://www.cloudways.com/en/</a> is one of the finest examples of PaaS built on IaaS.