1. Where you are in your career
2. How important control is to you
3. Your frustration level with traditional publishing
4. How comfortable you are with risk
Going Indie requires an Entrepreneurial spirit. There is risk involved when you decide to wear both a publisher's hat and an author's hat. You need to step outside your comfort zone, be able to make decisions, and you'll have only yourself to blame when things don't go as planned.
But if you have the spirit, and control over your own intellectual property is important to you, going Indie gives you so much more flexibility in how/where/when/for how much your books are sold.
So how do you decide? Take stock of where you are and what you want for the future. Much like I'm going to do here.
Where am I in my Career?
How much Control do I Want/Need?
Once I felt comfortable in the writing/publishing world, it made sense for me to seek the next level. I am a bit of a...erm...control freak. That is, I like to have some say over how things are done that affect me. Scratch that. Truth be told, I like to have complete say in how things happen that affect me. I can't always get that control, but in this one thing...my writing career...I can and do have control because I'm publishing most (soon all) of my books myself. Fortunately I'm fairly technical and don't break out in hives when I have to learn how to do new things online. So that made the idea of becoming my own publisher more than doable.
How Frustrated am I With my Publishers?
I love the publishing houses that decided to take a risk on me when I was brand spankin' new to the writing world. I feel a sense of loyalty to them that will never go away. But they are necessarily limited in how much they can do for me or my books because I'm only one of hundreds of authors with thousands of books. I get that. I didn't decide to go off on my own because I have animus against them for how they treated me. Well...not entirely anyway. #:0) I did it because it was the best business decision for me. And to be fair, I wouldn't have had as much success on my own if my publishers hadn't given me the time and vehicle to create a name for myself.
How Allergic am I to Risk?
I've made some mistakes, but most screw-ups are totally reversible. There aren't many things you can do that will permanently destroy your career if you go Indie. Of course you could get into a flame war with a reader/reviewer/vendor, but you could do that as an author in a publishing house too. The key to limiting risk and enhancing success is to always approach everything you do with professionalism. Choose writing as your career. This might sound simplistic, but some of the best authors I know haven't done that yet. They think they have, but when it comes down to it, they are unwilling to take the steps to really make it happen.
For the most part, Indie authors are serious about their careers. They have to be because everything success, every milestone, and every failure rests solely on their shoulders. It's a sobering and exhilarating place to be. And I'm lovin' every minute of it!