I've had this same thought about youtube recently. I have a channel which deals with one very specific area of my recent interests, but I've found it restrictive to only be able to make videos about that one area. I think, though, that because it's so focused, a lot of my subscribers would think "What???" if I started posting about other things. I think it helps to get subscribers faster because I stuck to a narrow field of interest, but I feel a bit trapped by it now. I guess there's pay offs both ways. Maybe you can have a sort of ratio approach. 95% this and 5% that, or whatever. To be honest, I also tried this, and although people react well to my other types of content, my stats show that it's the narrowly focused stuff which actually picks up the subscribers... I really do think it's very important to feel creatively free though. It's wonderful to express something true about yourself and have people, no matter how few, acknowledge and get something from it. It's a great feeling.