Pro Sites: Free Level?

When I started to set up my WPMS site with Pro Sites, I was told that FREE is automatic and not a level. So, tonight I look at the video on the Pro Sites plugin page and lo and behold, Free is being used as a level. I'm all confused now.

Why put Free as a level if it's automatic? I'd like to be able to discontinue a free level in the future if it's successful.

Thanks!