Diversity? If you want to reach out to different audiences then you have to cater to them. For a gaming channel I would think there's broad categories: Indies, FPS, Minecraft, AAA titles, Retrogaming, Scary Games, Mobile etc...
Then under each there's sub categories of: News, Reviews, LP, Achievement guides, cheats, etc...
So... depending on what your current audience is, go and try to target a new one? Make sure there is some overlap between the new and old and it should be entertaining for both.
Not a gamer so I'm not sure how much of that will work, good luck.