I've read quite a lot recently about what it takes to succeed as a writer. I define success as achieving a sustained career in professional markets, whether in short fiction or novels (although novels are the more high-profile and profitable of those two options.)
There is a certain amount of talent and luck involved in achieving success. If you don't have an active imagination and an innate understanding of how to tell a story, you probably won't make it as a writer. (Of course if you don't have those things, you probably wouldn't want to make it as a writer.) However, talent and luck alone won't be enough if you're not willing to put in the work. The professional writers I'm aware of write 1,000 to 1,500 words a day. Some do more, but very few write less.
I do not write 1,000 words a day. I'm doing well if I can average 500 a day over the course of a week. There are two major reasons for this. First, writing is not my No. 1 priority; my family and my day job come first. Secondly, after almost three years of writing original fiction, I am still in what I consider to be the learning phase. Yes I have a few sales, and I am proud of each and every one of them. But in general, I spend more time revising stories, trying to figure out what works best through trial and error, than I do writing new material. I aim for quality rather than quantity and (hopefully) am learning the techniques that are necessary for writing good fiction.
In the fall of 2012, my youngest child will start kindergarten. When that happens, I will have several hours most weekdays in which I will be the only person in the house. My plan for those hours is to unplug the phone, turn off television and Internet, and produce some serious daily word counts. That is when I hope to take off my training wheels and make a serious push toward turning pro.