Reduced operational costs

As the infrastructure is fully managed by the cloud vendor, it reduces the operational costs since you don't need to worry about hardware failures, applying security patches to the operating system, or fixing network issues. It effectively means that you need to spend less sysadmin hours to keep your application running.

Also, it helps to reduce risks. If you make an investment to deploy a new service and that ends up as a failure, you don't need to worry about selling machines or disposing the data center that you have built.