When it comes to writing, everybody knows that the rule of thumb is to not quit your day job. It's got to be a labor of love (much like getting an immigration visa for your foreign born bride) because it's going to be so much work and hardship your feelings HAVE to be legitimate for you to follow through.
To that end, the latest craze of print on demand publications makes a certain amount of sense. If you've already taken the time to build your audience and you know that you can move 1000 copies for example, why not produce an attractive POD to offer for sale?
Well, there are a couple problems with the POD model. First, you, the author has 100% control, and contrary to popular belief, that isn't always a good thing. Frankly, most works are greatly improved if one or more editors goes through them with the author.
Now, I've always been especially "ornery" when it comes to having people tinker with my works, but when I was working on "Dominvs" with epress-Online I had to grudgingly admit that the suggestions of my editor were right on. You can probably guess that this caused a bit of consternation for an especially arrogant bastard such as myself, but I decided to use it to my advantage and improve three or four other things that my editor never mentioned along with the one or two things that she did. That way I was able to absorb my editor's criticisms constructively and burn off my natural irritation for being edited (which everybody feels) in a way that made my book exponentially better.
It's sort of weird how there's plenty in every book that you KNOW needs to be fixed, but when you're in the early stages (submitting it to publishing houses), you just can't see them. It's not for lack of motivation because you want to send out the best book possible, it's just that somehow certain flaws don't make themselves apparent until it actually becomes a reality that your work is about to go into publication. The point is that you NEED somebody to take the time to go through the book with you at least once, and most POD places don't offer that (or if they do, they charge you an arm and a leg).
The thing that makes the current publishing industry interesting is that there are so many different ways you can get your stuff out there. Blogs are a way to develop a huge following, as are ebooks, PODs, etc. I especially like these small presses like epress-Online that produce an edited POD and market it. This is really an effective model for creating what is a professional piece of writing, without going through the highly competitive (and highly-conservative) route of traditional publication.
However, I would have to caution against going with the straight POD route. That might be a good thing to use to generate the necessary motivation for finishing your first book (it can be tough to continue writing if you believe deep in your heart that there will never be a way to "get it OUT there"), but when you've polished your style a little more, sooner or later you'll have to find a way to get an editor to work with you.
Still, as everyone says, the most important thing is to simply write as much as you can as often as you can.