On the Home page you will find a section titled "Subscriptions" that looks like this:
When you signed up for a Nerdio account you essentially subscribed to certain items. There are three base items - user licenses, SAN storage and server memory (vRAM). Additionally, some customers subscribe to other items such as SQL Server license as shown in the screenshot above.
In the screenshot above you will notice a warning image under the "Available" column for SAN Storage. NAP will show a yellow warning sign if used amount exceeds 80% of purchased amount and a red warning if used amount exceeds 90% of purchased amount.
You can purchase additional subscription items. See this article for further information.