The SmartVPS platform is generally for people who prefer to manage their hosting plans themselves. It is up to you to create your hosting plans, manage their resources, and make sure they fit into the resources provided by your SmartVPS plan.
Of course, you can still use the SmartVPS platform as a single-site solution - you get a full-featured hosting account which acts as a master account, and you are free to use it as you want.
It is important to note that child accounts cannot get support directly from our technical support team. Thus, it is up to you to provide support to your end clients with child accounts. In case something goes wrong, they would have to reach out to you for assistance. You may contact our support team on their behalf for assistance with any hosting-related issues.
If a certain child account needs more disk space or inodes and/or you want us to provide direct support to the customer, you need to get a single-site hosting account (e.g. a Business plan) for them.