The obvious reply to this would be both. So let me expand. Which is more predominant in your motive for being authors/writers? I find that writing for me is extremely personal, and my reasons are entirely selfish for writing. Of course "selfish" brings with it negative connotations but in this context I think it's perfectly reasonable. I'd love for others to enjoy my writing but my motive for writing is far more to serve as my creative outlet than it is to please others. What about you guys?