On the day he launched Grindr — exactly 10 years ago this Monday — founder Joel Simkhai said the only phone call he received was from the competitor, Manhunt, with a buyout offer of “$20,000 or $35,000.”

Simkhai declined.

But after actor and comedian Stephen Fry demoed Grindr live on the British TV show “Top Gear” a few months later in June 2009, everything changed. Simkhai said there were 10,000 downloads overnight and it “felt like every gay man knew about it.”

“It’s basically a gay cruising application,” Fry told “Top Gear” host James May. “Get this, when you load it,” Fry said, “up appear all kinds of faces and pictures. And what’s so amusing is, you press them and it goes like, ‘Hi, I’m Mike,’ and it tells you how close they are — it says 20 yards away.”

Now, a decade after Grindr first launched in the App Store, it has an left an indelible mark on the gay and bisexual community. Countless gay men have met their life partners, formed relationships, met friends, and traveled the world with the support of gay family thanks to the queer digital space created by Grindr and the many apps it inspired.

Historically, Grindr was the first iPhone app to combine dating — and sex — with geolocation, birthing a genre that today includes favorites like Tinder and Bumble, which are popular with the larger heterosexual user base.

But in Grindr’s case, it has remained irresistible because of its central function, which remains unchanged a decade after its launch: the near-magical ability to reveal nearby gay people — a sort of tech “gaydar.”

Joel Simkhai attends An Evening at the Bowery Bar at Bowery Bar on March 23, 2010 in New York City. Patrick McMullan / Patrick McMullan via Getty Image

As Uber defined the genre and Lyft came after, so Grindr did for Scruff, Jack’d and Hornet. Today, Grindr has more than 3 million daily users in nearly 200 countries — perhaps the largest “gathering” of gay people in history. And yet, a decade after its launch, Grindr is ranked highest among apps for making its users unhappy.

According to the Center for Humane Technology, data from 200,000 iPhone users found that 77 percent of Grindr users who use the app more than one hour per day said doing so made them unhappy. Also included in the top five were two Candy Crush games, plus Facebook and WeChat. Longer daily use of those apps also correlated to greater levels of unhappiness.

“A large number of users launch Grindr hourly and daily. Some guys leave it open for several hours a day,” Simkhai said in a February 2010 press release, in which the company announced a $2.99 monthly subscription “to view up to 200 guys.”

According to Los Angeles psychotherapist Gregory Cason, he’s seen patients fall into a sort of “behavioral addiction” to Grindr and other apps that can make users feel aroused.

“We do know that people can have an addiction to these apps that’s similar to gambling addiction, because it works from the same principles,” Cason said. “They can get to a point where their brain constantly wants to check.”

Variable ratio reinforcement is a behavioral psychology principle where a behavior — like checking Grindr, or pulling a slot machine lever — creates a positive or negative “reinforcement” that arrives unpredictably, like winning a jackpot.

In Grindr’s case, Cason said, the reinforcement is the anxiety reduction that comes along with sexual arousal: anything from having great sex to feeling vaguely turned on from a naughty chat. All that, Cason said, can cause someone to repeat the activity in order to reduce anxiety.

As it turns out, he said, variable ratio reinforcement is one of the most effective ways to produce a repeated activity, harmful or not. A Grindr user who spends a lot of time scrolling through the app before scoring an incredibly positive — and unpredictably timed — experience is more likely to continue to use the app, even if doing so harms their social or personal lives, Cason said.

“It's a hard thing to control at certain points. Not everyone can,” Cason said. “And we can't just say it's just the app,” Cason said. “We also have to take into account somebody's insecurity, or if they're lucky enough to be more attractive, that might get more reinforcement too.”

One user, J.R. from Bakersfield, California, who like others asked that his full name not be used so he could speak freely, said insecurity fueled by Grindr’s rampant bullying made him use it more.

Grindr helped mainstream hateful phrases like “no fats,” “no femmes,” “no Asians” and “masc4masc.” The rampant racism, femme-shaming, and transphobia experienced by so many of Grindr’s users even spawned a lawsuit.

Grindr responded last year by launching a feel-good content campaign called Kindr, which encourages people to stop cyberbullying. “Kindness is our preference,” its website says.

J.R., 33, said “kindness” is not what he experienced as an overweight Grindr user.

“I had two opposite experiences as I used it when I was overweight, and then again when I was thin,” J.R. said.

“I did have people who would just message me to call me horrible names like ‘fat pig’ or ‘disgusting,’ and then after they had their two cents, they would block me so I couldn't respond,” he said. “This rejection crushed my soul. I would get super angry, or depressed, or even more aggressive in finding someone to hook-up with.”

J.R. said he found a completely different experience after he lost more than 60 pounds and logged back on. “People were bombarding me with complimentary messages and sending me unsolicited nudes,” he said.

“And I have to say, the flattery was intoxicating. Where it used to be negative energy and insults, it would suck all the life out of me and was jading my self image and how I felt about our community,” J.R. said. “But once I was ‘acceptable,’ the attention I received was like a drug. I loved it and wanted all I could get.”

Other users, like Chris, 22, from Orange County, California, knew about Grindr before he knew he was bisexual. When he downloaded the app, he said he had already developed a sense of confidence that he knew not all other guys at his age had.

“There’s no other way but to dive into the app and really go for it,” Chris said. “You learn what you like, what you don’t, what kind of people you’re into, and what kind of dialogue you’re into as well.”

Grindr

Not long after he started to log on, Chris saw Grindr’s underbelly: the widespread use of coded language by users who are looking to buy, sell, and share drugs — particularly crystal methamphetamine — known as “partying and playing.”

“I knew to stay away, that that wasn’t something that I would like to partake in, so I would kindly decline or kindly block,” Chris said. “I had to look it up, the terms. Because there’s different jargon with our community.”

“It’s almost like a rite of passage for the culture,” Chris said. “You go from zero to 100 real quick.”

But like many men, Chris used apps to chat and make long distance penpal-style friends, some of whom he’d meet in real life. One of those people was Jason, 53, a bisexual man from rural Oregon.

Jason said he came out as bi at 19 and he knew about the apps throughout his monogamous marriage to his wife.

“I was really worried that it would be a vending machine for dick,” Jason said. “And it can certainly be used that way — I see the potential.” But after a younger family member came out of the closet and Jason had a health scare, he said he realized “there's this whole side of myself that is not finding any expression.”

“I didn't realize how important it was until after I had that awkward, amazing discussion with my partner,” Jason said.

Thanks to gay dating apps like Scruff and Grindr, “I was able to, for the first time since I was in my early 20s, have sex with a guy again and be like, ‘oh yeah, this whole side of myself, holy cow, this completes the circle!’”

Jason has used these apps to meet four or five people who he now considers his best friends. He even developed a long-distance chat relationship with Chris, who lives in Southern California. Jason said it’s almost never just for sex.

“I’ve been able to make friends and meet people who have gone through the same things I have, and are exploring the same areas I am,” Jason said. “We can do it all without actually having to be in physical proximity.”

Indeed, a decade after their launch, Grindr, Scruff, and other apps have become critical tools for building queer community in rural places where gay bars largely don’t exist.

“Grindr was first to market and just bought this idea that queer people are everywhere, and we should actually be able to see the queer people around us,” said Mathew Rodriguez, a staff writer at Out and former staff writer at Grindr-owned Into. “The idea of actually making the world accessible to queer people — that is, to me, an evolution of everything that queer people have been working toward for centuries.”

“Now that we live in a post-Grindr world where the mask is off, what we know is that there are gay people all around us,” he said.

“I actually think that the next step is going to be about addressing some of the underlying causes of our anxiety and our loneliness, because I think that's the question that we're always getting toward: how do I feel less lonely,” said Rodriguez. “The next step has to be about intimacy.”

Simkhai sold a majority stake the app in 2016 to Beijing Kunlun Tech Co. in a $93 million deal that valued the company at $155 million.

Simkhai said one of the things he is most of proud of is Grindr4Equality, the app’s advocacy platform. “Once we had that realization that, ‘hey, you have the number one audience of gay men — what else are you gonna do with it? The answer was, ‘hey, maybe we can mobilize all these men to do different things,’” he said, giving examples like voting, signing up for PrEP and rallying for LGBTQ rights.

“The LGBT community should be proud, once again, that we paved the way not only for the Tinders of the world, but also the Ubers of the world,” Simkhai said. “What Grindr did was really put you as a user in the center of the world — and I think that was I think that's what the revolution of Grindr was.”

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