Sara, as much research as I have done and experiments, I know publishing twice a day or more actually works. But I don't do it. I know it won't overwhelm my audience because most times people will just put a story in their reading list and come back (usually same day).
I have grown and earned pretty decently, but I usually publish about 15 to 20 stories a month. Publishing daily and most importantly twice daily will grow your audience and your earnings.
I'm so stubborn, sometimes. Must be the Scorpio tendency.