I have seen this done only on a handful of forums but in some cases, it does work out really well especially if you have a credits system and a shop system on your forum.
Allowing members to have their own forum section can allow them to post their services, work or even just use it to share stuff they enjoy. Allowing this to be possible with a shop addon and a credits addon means that the system will not get abused either as it has to be approved before becoming active.
Would you allow members to have their own forum section?