Debating Styles

I have been fighting this for a long time: establishing a "style." When doing freelance illustration, I'm finding that my mentors weren't lying when they said you have to define your style as your unique product... that when they call you, they should basically know what you're going to do before you do it. I love the idea of growing, learning, experimenting, and rarely have enough free time to do it outside of paying work (don't be mislead, I don't do a LOT), but it's getting to where I feel I need to streamline, simplify, or just CHOOSE what I'm going to do from now on. I have several ideas, including marketing as a 'studio' with a look, or even marketing myself as 3-5 different artists! This isn't too crazy, if you think about it - it'd satisfy my creative and explorative itch. (was that even worded correctly? o well.) I'm sure I'd get sick of the demand for one of those styles, but I think it's time I define my 'product' for illustration. The frustrating thing is, I feel like I could do almost any gimmick and whatever happens to be 'hip' or popular at one time will be far more successful.. and WHO knows what those crazy editors and art directors will find kitch?!
Here are two illustrations I did (compare to work on my website, if you want to see what I mean) that were low-paying and I told the art-directors that I didn't have a lot of time, nor could I put a lot of rendering into it: that I'd do a quick cartoony look. The robot is from about 4 months ago, the pig from this week. They're usually pretty cool with it, but I'm wondering if I shouldn't just do it all the time and save myself the guessing game.