sometimes you make things more complicated that they do cheat-master.. lol
offering free hosting is not opposite to use a paid software... imagine if the owner just had in hands an old license of vbulletin for another site... you never know.
btw, most of the free hosts i know are also offering paid services on another site because they have a large target...
For those who don't understand what he's trying to say.
Those who offer free forum hosting (an example: invisionpowerboard.com, phpbb, etc, or better yet, some forum that no one knows much about) are using vBulletin as their support instead of the one they're offering to others. I do find it funny.