Interesting conversation.
I myself have recently considered posting on Nifty, but, I'd have to write a story I don't give a crap about first, I think. I say that because I'm not going to argue with the Nifty Gatekeepers over who has the rights to the story, especially when their TOS pretty much states that any rights I had as the author are null and void because they're a) lazy and holding me up for money in order to get anything done.
That said, I can say that Nifty wasn't always that way. I wrote stories back in the late 90's as a teenage lad of about 16/17, (no I won't ever tell anyone the titles), and I had a very good relationship with one of the archivists for one of the mirror sites. I believe his name was Dave and he lived in NY (or I'm thinking about Dabeagle), and the archivists actually gave a crap back then. I'm not so sure they do now, but then, I haven't emailed them recently or submitted anything.
That being said, I also have to agree with Vic. 90% of the material on Nifty is utter crap. It's like opening a bunch of clam shells just to find that rare pearl. Talk about boring and tedious, but nifty is what ultimately brought me here, along with "The Other side of Me" by Dom Luka. So yes, it has its uses, mainly, if you post a story, tell the readers in your disclaimer where they can find more of your stories: Here. You can do that by providing a link to the site within said Disclaimer.