Write a story that you may have to shop around several editors even if you're an established pro, that you won't get paid for until several months after you submitted it, that you may never get any letters of comment about at all -- or write a story that will get you feedback within hours of your being sufficiently satisfied with its quality to post it online. For many people the choice isn't automatically in favour of the money.

That is such a good point. I started working on a novela a couple of years ago, and after I had a few chapters in place, I sent copies to a few RL friends of mine who I thought would appreciate Fantasy. I got very little feedback from them except from my mother, who liked it, but couldn't understand it. In the end, (I've added a few chapters since then, and I'm about half way through) if the story never sells, I'm sure my online friends will read it and send feedback, and that will probably be okay with me.