Portal Experience, Quota Reached Msg

Hi guys.

It's been 3 days since I tried to host my server, which has been published and authorized. It never works.

I'm getting this message saying that the quota of servers has been reached.

But I see that there's no shortage of other private servers online.

What's the cause of this?

Ancillary question: I remember it saying that only Premium players would be able to join my server. What are those?