What does it do?
This will add ads inside the first post message of closed threads. You can select several different options for displaying ads. Select specific usergroup to see ads in Specific forums only.
Grab the zip archive of plugin and upload it to the root of your forums. Then activate this plugin directly from your AdminCP Plugin Manager.
Go to: ACP > Templates > Post Bit Templates > postbit > and find;
and change it to;
Sorry, but you need at least 25 posts and 5 hours online time to unlock hidden content.