(Thanks Helen - I will definitely look that up. I once wrote a parody fanfic in which I used the verses of Barry and Freda as prompts!)
Cruella - I don't think it's quite what you meant, because it isn't a subscription service, but I write and read stuff on Archive of Our Own, which is a fanfiction site funded entirely from user donations (unlike the Fanfiction site, which is funded by advertisements). Fanfiction sites are culturally interesting in that they are predominantly female spaces - majority women writers, writing for a majority female audience (albeit women who live in the real world, surrounded by all-pervasive male sexuality and male sexual violence). AO3 is not a porn site - there's all sorts of stuff on there - but it undoubtedly has a lot of porn on it. It has a system of age ratings and "tags", i.e. descriptors telling you what to expect. Thus anything - whether straightforward missionary position sex through to some pretty eyewatering stuff - is labelled upfront so you know what to avoid (or conversely what to search for). Insofar as it's funded by users, I suppose it's "paid for", and insofar as it has some fairly hardcore stuff, I suppose it meets your criterion of sharing space. So yes, I do use such a site, and have no qualms about it because it's written words - figments of someone's imagination.
I suppose the moral issues I see coming up are:
Are real people harmed? - Not in the case of words.
Does this encourage people to engage in sexual violence? - In the case of a fanfic site, no, I don't think so.
Does this normalise sexual violence? - Again, no, I think, because it can be seen in context as a minority niche interest among a lot of more normal interests. (Some fandoms seem to attract more kinky stuff than others, mind you.)
Is the stuff on there going to trigger people who've been victims of sexual violence? - No, not if it's tagged correctly, and it generally is.
Does it contribute to rape culture, by making rape seem like an acceptable part of the spectrum of normal sexuality? I don't think it does. It is presented as a fantasy, and is counterbalanced by enough (the majority of stories) where normal sex is seen as healthy and rape is seen for the act of violence it is.
But I have spent a long time thinking about (and talking to writers about) why some women write fantasies which eroticise rape. (Thanks to the AO3 tagging system these are fairly easy to avoid, fortunately). The reasons are multiple and complicated, I think, and it's certainly not a straightforward causal step from "woman A has written a rape fic read by women B, C, D and E, therefore man X will think it's a good idea to go out and rape women because some women like that sort of story."
So here's a list of possible reasons why women write rape fantasies (not complete, partial, my own speculations, possibly patronising because I hate rape fics and really can't get my head round why anyone would want to write them).
- Sexual repression. Not much of a thing in Western Europe, but there are (having talked at length to American women about this) still very socially conservative tracts of middle America where women are brought up to think of sex as dirty, and thus find as adults that the only way they can "let go" is to imagine themselves being overpowered.
- Society-wide Stockholm syndrome. Male sexual violence is ubiquitous, so some women deal with the cognitive dissonance caused by the threat of it by internalising it and eroticising it - de-fanging their worst fears by re-imagining it as something that (in the right circumstances, with the right devilishly handsome man) they might enjoy.
- Rape survivors dealing with trauma. Some rape survivors find writing a useful form of DIY therapy - they get to re-write the narrative, but this time, because they are the author, they are in control. They get to decide how far it goes, or when it stops, or whether there is any sort of closure.
- The all-pervasive nature of male porn. Some women have watched so much male-oriented violent porn they have genuinely internalised the belief that sexual violence can be erotic.
- They have abusive tendencies themselves and are infact identifying with the rapist rather than the victim (this is a horrible one, and a very minority one, but I would say it does exist).
- They are from incredibly patriarchal societies and don't realise rape is wrong. (Remember fanfic is a world-wide phenomenon). I had an exchange of messages with one young woman in the far East about this - I told her she was writing a rape fic, she claimed she wasn't and that I was naive about "what men are like". In her world, the story she was telling was of a man who fancied the woman so much (a compliment in her mind) that he couldn't help himself, but as the story developed, he would learn to love her and develop respect for her. Screwed up thinking, but a product of the society in which she lived.
- Authorial stupidity. Our writer has Fred and Bertha as her OTP ("one true pairing"). She knows (because she's the writer in control of the plot) that Fred and Bertha are meant for one another. She knows that Fred fancies Bertha, and knows that Bertha reciprocates. She knows that if Fred makes a move on Bertha, Bertha is going to say "yes please." So (and this is where the authorial stupidity enters the story) she has Fred initiate sex while Bertha is asleep. Because the author can't make the imaginative leap to realise that while she, the author, knows Bertha wants it, and Bertha knows Bertha wants it, at this stage in the story Fred does not know that Bertha wants it, and is therefore committing sexual assault.