I found a couple of blogs which discuss free science fiction. One of the reasons I plan to write science fiction short stories here on my blog is that I see little value in trying to get them published. The financial incentive is not worth the wait, and would not enough to allow me to quit my day job. Basically my goal is to build a fan base, people who are familiar with my work and might buy my novel when it is ready later this year. The first blog I found is BestScienceFictionStories. Their post on The 10 Best Web Sites for Free Online Science Fiction Short Stories is very useful. Hopefully my site will be on the list soon.
Tor Books offers free science fiction downloads every week just for signing up. Not sure if they ever have science fiction short stories. This week's book is In the Midnight Hour by Patti O'Shea. The next book will be Battlestar Galactica by Jeffrey Carver.
They don't appear to have a science fiction blog.