I've had some success on a couple of these. Thousands have “Liked” my short stories at Venture Galleries and the now defunct The Writers Collection, as well as my own website/weblog. I recently received an invitation to publish my short stories on a new one, ReadWave.
These websites are there to help you discover new writers, ones who tell stories you like to read. It's a lot easier wading through a lot of badly written prose looking for the gems when the stories are short.
Many famous authors began their writing careers penning short stories and serialized novels. Ray Bradbury. Louis L'Amour. Jack London. Mark Twain. Charles Dickens. In times past, they were published in newspapers and the pulps, cheaply produced magazines, as well as glossies, magazines printed on polished paper. These media have largely disappeared, replaced by websites. They provide an opportunity for readers to get to know writers and their style before they commit time and money to read their full length novels.
Please look me up on these sites and tell your friends. You'll be doing them and me a favor.