Mainstream America is just starting to learn about transgender people, thanks to Caitlyn Jenner's momentous interview with ABC's Diane Sawyer and shows like "Transparent." But in the porn world the popularity of transgender porn has long been the industry's open secret.

Transgender people say time and again that they want others to accept them for the gender they identify with, rather than the gender they were assigned at birth. And for better or worse, straight men who buy the majority of transgender pornography starring trans women are more than happy to comply with their wishes.

“Over the past 15 years we’ve watched viewership of content featuring transgender performers skyrocket," Jeff Dillon, VP of marketing for adult e-tail site GameLink.com, the self-styled "Amazon of porn," told International Business Times.

"Jay Sin's TS Playground #20" is the No. 1 selling porn title on GameLink's site this week, No. 12 is "TS Beauties" and six other transgender porn titles are scattered throughout the top 100 list.

But how does this affect the lives of trans people? Is trans porn merely the sexual fetishization and objectification of trans bodies, or has trans porn helped to drive the social acceptance of transgender people?

HAVE A BLESSED DAY @Caitlyn_Jenner ! YOU INSPIRE ME TO BE A BETTER TRANSWOMAN! GOD BLESS U&Ur FAM ALWAYS! pic.twitter.com/ZNoFZ7a9QQ — Vaniity (@Vaniity) July 27, 2015

Dillon likens porn's early-adopter attitude with transgender people to its role in racially integrating porn.

"In the 1970s, we introduced the world to the first images of interracial [black and white] couples having sex in the movie 'Behind the Green Door,' " Dillon said. "This was incredibly shocking at the time, but it soon became mundane. I believe a similar connection can be made between porn and the rapid acceptance of other social/sexual shifts, including same-sex marriage and gay rights, ethical nonmonogamy and swinging, and now transgender rights."

Top Seller Since The 1990s

Offering transgender porn is not exactly bad for business. Lest one begin to envision porn execs arm in arm, singing "We Shall Overcome," it helps to remember what drives the porn industry: Money and consumer demand. And the demand for transgender porn has steadily increased since the 1990s.

When asked if transgender porn was his most popular genre, porn studio Evil Angel VP Adam Grayson answered: "In terms of revenue per scene or movie? Hands down, without a question. Nothing even touches it. And it's been that way for decades, since the early days of it. And we sell it at a price premium. Let's say an Evil Angel wholesale DVD is in the $15 range. A trans release, same packaging is $19. Why? Because we can get it."

Photo: TS Playground/Evil Angel

Grayson said that the popularity of trans porn is talked about all the time among industry insiders, and all agree that among their numerous titles and satellite websites, trans porn tends to be the most popular.

"It's [trans porn] always been on the fringe, but a wink-wink, nod-nod -- everyone knew it was a money-maker," Grayson said. But the underground treatment of trans porn might end soon, thanks largely to Caitlyn Jenner.

"I had someone at a major media company earlier this year tell me that it was increasingly hard for them to say they couldn't put transgender porn on their adult platform when Caitlyn was about half of 'E' channel's coverage," Grayson said. "Corporate America realizes that that would be the equivalent of saying 'you can't have black people porn.' So I believe that Caitlyn Jenner is single-handedly going to bring our TS content into more living rooms in the next few years."

On the free porn site PornHub, which offers 69 different categories of porn, the so-called "shemale" category ranks 22nd in most searched, with 1.51 percent of all category views. Although that doesn't sound like a lot, a PornHub data team member explained: "Shemale’s 1.51 percent of category views is still quite significant when you consider that Pornhub sees 60 million visitors per day. Over the last few years our search and category diversity has grown, so individual types of porn are smaller proportionately." The number one searched category is lesbian at 6.39 percent, while amateur, for example, gets 2 percent.

Terminology Trouble

Although the preferred term among most transgender people is "transgender," the porn world still uses the word "transsexual." This term is considered by LGBTQ rights organization GLAAD as an "older" term used to describe trans people who have changed their bodies through medical interventions, which not all transgender people want to do. Archaic terms considered by most transgender people to be derogatory, like "tranny" and "she-male," are also often still used in trans porn titles -- largely, Adam Grayson of Evil Angel told IBTimes --for marketing purposes; that's what men are looking up on Friday night.

But the industry is bowing to some pressure. In 2013, the previously named "Tranny Awards" hosted by transgender porn site Grooby was renamed "The Transgender Erotica Awards." And Grooby even co-hosted a “Trans Talk” panel in July, offering “ a lived experience education around pronouns, sexuality, labels in and out of the adult entertainment industry, and much more." But Steven Grooby insists that "she-male" is a "porn word" and that although he wouldn't use it outside of the context of porn, it would be business suicide to switch to "transsexual," much less "transgender."

Google Analytics, he argues, bears this out. In a comparative analysis "Shemale" has 2.74 Million hits, "Tranny," 450,000 hits, "Tgirl" has 90,500 hits, and "Transsexual" has 60,500 hits.

Transgender porn is also among porn production company Devil's Films number one genres, always in the top three of their new releases, Steve Volponi, VP of sales and production for Devil's Films, told IBTimes. Although the Internet has just made it easier for straight men -- its primary audience -- to buy transgender porn, they've been buying trans porn since it became available.

"When I started in retail in 1991, these guys would slip into the [trans] section, grab one and sandwich a transsexual movie into the straight ones, and then they'd say, 'It's a joke, I'm going to give it to my friend,' " said Volponi. "Let's just say I met a lot of people with friends they were playing jokes on."

The 1990s: The Birth Of Transgender Porn

"We were one of the first mainstream companies to release transsexual porn in the 1990s," Grayson of Evil Angel told IBTimes. "We're one of the market leaders, and release between two to three titles a month. But Grooby is the market leader: trans porn is their entire business."

The genre's mainstream clout could be credited to Joey Silvera, once a straight porn star himself in the 1970s, and who is considered by many to be the "Godfather of transsexual porn," according to Grayson. His breakout trans porn film? "Rogue Adventures," which came out in 1999.

"Not a lot of his peers were doing this," said Grayson. "And frankly, he's a millionaire as a result of it."

Trans porn was initially categorized in the gay section of the porn aisle in the 90s, but it became clear that straight men -- "kinky straight men" according to trans porn star veteran Wendy Williams -- are the primary demographic for trans porn.

Trans Porn: Good For Trans People?

"What's exciting to me is the expansion of what we understand to be normal and abnormal sex acts and bodies," said Celine P. Shimizu, Visiting Professor in Cinema and Sociology (Sexuality) Studies at San Francisco State University and author of "The Hypersexuality of Race" and co-author of "The Feminist Porn Book." "I find the emergence of pornography itself is useful in our society where the language of sex acts is so limited on screen, so there's always been an element of sex education in pornography."

Shimizu cautions seeing trans porn as inherently progressive, however, and she says that it depends on just how fetishistic or obsessed with genitalia the porn is.

"A rise in the interest of trans people doesn't necessarily translate to recognition of the struggles of people who live those lives. So fetishism isn't simply positive -- it can aggravate their exploitation," Shimizu told IBTimes. She argues that although the exposure to trans porn could lead to the decreased stigmatization of trans people and an increase in cis-gender/transgender coupling -- this in itself would only be progressive if the trans person were seen in his or her complexity, and his or her struggles were recognized, she said.

"Consuming ideas and seeing representations of people allows people -- for better or worse -- to acknowledge a humanity that's out there," Dr. Chauntelle Tibbals, sociologist and author of "Exposure: A Sociologist Explores Sex, Society, and Adult Entertainment" told IBTimes.

'Trans Is The New Gay'

"I don't think tranny and she-male are slurs," said Wendy Williams, who has been in the adult industry for 13 years, since she transitioned at age 28. "They were words initially used so the laymen person could understand the products they were buying in porn. There are more issues we have to worry about: suicide, the homeless rate, getting an education and finding jobs as trans women."

"When I hear these activists going after 'tranny' and 'shemale' -- that is wasted on words," she said. Williams just got through wrapping up the production on a porn parody of Caitlyn Jenner's coming out -- called "Kaitlyn Gender."

"When the director asked me, 'Do you think this is going to offend anyone?' I said, 'Porn is not about morality,' Williams said. "But the idea is not to belittle the transitions of trans women. It's that the mainstream media is so wrapped up in the genitalia of an athlete. That's news! Some people are going to say 'too soon!' But porn has always pushed the boundaries of social morality, pushing boundaries of what people are comfortable with."

Photo: Dusti Cunningham

Buck Angel, a pioneer in a yet-to-emerge genre -- trans men porn -- is equally frustrated with trans activists who shun trans porn stars and argue they're bad for the community. When he started BuckAngel in 2004, he wasn't really sure who his audience was, and thought because of the women in his life -- it would be cis-gender women. The reality? It's gay men who watch trans men porn, for the most part. In addition, he noticed people were coming to the site to learn more about trans men.

"At first, it wasn't that I wanted to make the work educational," Angel told IBTimes. "But I soon realized it is. I am educating people on what it is to be a trans man and be sexual in your body, educating them on transmasculinity. But I've fought against my own trans male community telling me, 'You don't represent me. Thanks to you, everyone's going to think all trans men like their vaginas.' [Angel has not had bottom surgery.] But I get letters daily from people thanking me about making them feel better about their bodies." Angel says he thinks that the trans community, in an attempt to normalize themselves, are also desexualizing themselves.

"But I feel like talking about your sexuality is part of being trans," said Angel.

'Porn Is A Cutural Leader'

Mark Kernes has been involved in the adult industry for 32 years, all of it working for AVN News and its website. He's been reviewing trans porn since the 1990s, and has seen what he calls the "slow growth" since then. But between Caitlyn Jenner and the increasing visibility of trans people in mainstream media, he says a few shifts are evident.

"Normally, trans movies don't have plots; they're just a series of scenes. But we've noticed in the last year that there are movies with plots that revolve around trans performers, at a time when there's a downswing in plots in straight porn. Buddy Wood's 'She-male Secret Service' is about the president needing protection and some of the people on his security staff are transgender. 'Trannychaser II: Confessions of a Pool Boy,' is about a pool boy who is seeing a lot of transgender people on the job."

There are other signs in porn that trans people are becoming mainstream. The boilerplate storyline of "Transsexual Babysitter," based on conventional heterosexual cisgender porn, is modified in only one respect: the babysitter the husband goes after while his wife is sleeping is transgender.

Kernes also noted that more mainstream trans stars, like stars of "Ru Paul's Drag Race," are showing up at trans porn awards, more transgender porn stars are getting invited to mainstream porn events, and some male performers are crossing over from straight porn to do transgender porn.

"Trans movies are just accepted," Kernes said, and he connects their inclusion in porn to the normalizing of transgender people in society. "There have always been gay people in society. Gradually, they became more prominent, attained more rights, and now they can get married. I compare the development of trans material to that -- it's been that kind of progression. Porn is a cultural leader in that sense, but it's always been looked down upon by polite society."

[This article has been updated to include additional statistics of porn category searches on the free porn site PornHub.]