When you logged in to the admin area, on top left corner you see a label as 0 of 100 Sites. That means you can create up to 100 sites. But this limit is set to avoid any kind of system abuse. All members can create unlimited license. So, when you are about to reach a limit of 100 sites, we will add another 100 sites, and so on.
For now, don’t worry about site limit and just get started with creating few 🙂