Take a look at almost any of the example sites listed at:
http://www.nabble.comThe links will take you to pages like these:
http://elasticsearch-users.115913.n3.nabble.com/Update-mapping-td3957288.htmlhttp://activemq.2283324.n4.nabble.com/jars-needed-for-a-jms-client-application-td4713101.htmlhttp://guitar-fx-layouts.42897.x6.nabble.com/Best-slap-back-delay-td31604.htmlThose pages include adverts associated with the first and last posts in the topic.
It is those that you pay to remove with a Premium site.
If you haven't seen such ads then you are still in the trial period with your forum and they are not yet being displayed.
The footer is not something that can be removed without breaking Nabble's T&Cs - unless you pay for Premium Support.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.