I think will be awesome to have some new categories in Platform Builder Forums that may make it a more active place:
1.- Tutorial Forum: Here you can post a tutorial of how to do something in PB, I have a lot of things to learn and a lot of things to teach, this will be a good place to exchange knowledge.
2.- Team Developing: When you want to do a game with any other guy on the forums, you can ask help here.
