I think you all miss the point. Of course the whole thing is a business, but there are some rules to business - namely, someone should think long-term and not short-term. Of course Ariel might get some extra bucks if she just posted some b/g sets, but would it be a wise decision?
Porn is successful when it estimulates one specific part of our anatomy - and I don't mean the cock.
Porn is art. And art means that the artists must stimulate the IMAGINATION of the consumer. That's why series like Game of Thrones are an immense success while other series fail. That's why most people will watch soap operas where the girls doesn't know who are their parents and almost fucks with her brother (or father), while a plot without any twist is unsuccessful.
Even those called "reality shows" are only successful because they have nothing to do with reality. Who would watch a show about a family that lives in harmony, with a nice couple of parents raising adorable children?
Back to porn. Porn is no different. And the successful pornstars are those that can milk her fans for ages just by making them imagine things.
That's why teasing girls still have an enormous amount of fans. The are just imagining what small fraction of the tits, pussy or ass the girl will show next. That's why those british glamour models are so successful, the fans are just waiting to see which will be the next lezzying of them.
And that's why lesbian models and lesbians pornstars are so sucessful. For a purely heterosexual man, there's no better thing than lesbian porn. Two (or three) pretty babes doing each other, no dicks, and I can think myself into that scene. The delusion is that these girls are lesbians not because they hate men, but because they haven't found the right man (that's me! here I am!)
This delusion shatters whenever a lesbian pornstar does b/g. She's no longer my princess waiting to be deflowered by the brave knght (me, of course). Now she is a slut who betrayed me and fucked another dude. For a purely heterosexual man, that's the end of it.
But of course purely heterosexual men are a minority. Most men are bisexual, otherwise there wouldn't be so much sports fans.
And the bisexual men are those that will now consume the porn from this girl. But she can't just stay doing b/g, this is fucking boring, who wants to see a girl being fucked many times by one or more dudes? That's why whenever a girl does b/g, her (new) fans begin asking when she will do anal and DP. She is no longer the princess of the purely heterosexual man, now she is a slut who fucks everyone. And if she fucks everyone, then do it all the way - do anal, DP, DVP, DAP and even bestiality. As soon as she stops raising the bar, her career is finished.
Back to Ariel. If she really wants to do b/g, she should be aware that it won't stop there. Her new fans will demand more and more of her.