An IBISWorld report from September 2013, the most recent data available, puts the entire “dating services” industry at $2.1 billion in annual revenue. Some 68.7% of that pie, the report says, is from online or mobile dating services. But the market overall has grown 3.5% since 2008, and IBISWorld predicts it will grow by some 5% more in the next four years.

The dominant players in this industry are the ones you know: Match.com and OkCupid, both part of Match Inc., which is part of Barry Diller’s InterActiveCorp (IACI). IAC controls 28% of the dating industry. The next biggest is privately held eHarmony, with some 14%.

That doesn’t leave much room for smaller challengers to claim a large slice of the dating pie. But they continue to try. The number of smaller dating businesses is constantly multiplying. And perhaps the most prominent has been the mobile app Tinder, which has seen explosive growth and which many people may not realize came out of IAC’s research and development group. (As Match Inc. CEO Sam Yagan told Fortune last year, “We keep it sort of on the DL because it’s much sexier for it to be a totally fresh startup that has nothing to do with the market leader.”)

Each dating site or app has its own clear special sauce — the angle that it pushes to set it apart. There are services geared toward specific groups (JDate for Jewish daters, BlackPeopleMeet for black singles) as well as those that stress one focus or feature. eHarmony, for example, places a big emphasis on marriage; Hinge shows you only people with whom you have mutual friends; HowAboutWe offers couples planned activities. (It also has sought to build a media network by purchasing Nerve.com and other sites.)

Shayan Zadeh, CEO of Zoosk, doesn’t buy the idea that each site has its one special sauce. “We don’t subscribe to that mental model,” he told Fortune in an interview last month, before the company entered the quiet period ahead of its IPO. Instead, Zoosk seeks to have it all, rather than focusing on one narrow angle of the online dating experience. Its features summon the image of a supermarket: The aisles include SmartPick, Carousel, and Search.

Each of these features looks akin to the main idea of other, narrower dating sites or apps, though Zadeh rejects the comparison. SmartPick, which sends you one single targeted match per day based on your past behavior on Zoosk, is a lot like Coffee Meets Bagel, which does the same: You may like or reject the person and see if it’s a match, but you won’t get a new person for 24 hours. Carousel is Zoosk’s Tinder-like function, where you quickly scroll through faces and can give them a check mark or an “X” purely based on looks — if they like you too, you are matched. In Search, you may tailor your geographical parameters to only see those nearby.

In previous interviews with Fortune, Match Inc.’s Yagan has often compared different online dating services to a tool belt — the idea being that each site serves its own purpose. “I don’t think it’s crazy to have different tools in your dating tool belt,” he told Fortune in September. Zadeh and his company are attempting to have Zoosk be that tool belt, all self-contained in one site or on its app.

“If you think about dating as a spectrum,” Zadeh says, “there’s the casual hookup on one end, and then there’s someone serious about getting married on the other.” Using only a hookup app, he reasons — the very popular Tinder is typically labeled as one — would be “like saying I’m going to go to McDonald’s for a fine dining experience.” Instead, Zadeh says he wants to get out of those silos to create the Google of online dating. Then again, Zadeh and the Zoosk folks have often compared their service to a Netflix (NFLX) for online dating, thanks to a “proprietary behavioral matchmaking engine” that Zadeh claims relies on your behavior — which people you’ve clicked yes on, or even lingered on to view for longer before saying no — to get to know you. So, which is it? Well, maybe Amazon is the best big-company model comparison, Zadeh says, “because they do it all and they’re good at getting to know you.”

So, is Zoosk successful in its attempt to do it all?

A month-long test-run of found the mobile app to be clunky and overwhelming, with distracting alerts and prompts to purchase upgrades. Within Carousel, users do not have the option to input any geographical preferences; you may live in New York and get shown someone as far away as New Mexico, which doesn’t make much sense. One reason Tinder works so well is that two people who match could potentially meet up right away, easily — they’re usually only a few miles apart. Carousel came out two years ago, so it predates Tinder, but it lacks the addictive, tactile swiping feature that has made Tinder so popular and that has already influenced other apps. (Hinge uses the same swipe-right or swipe-left functionality.) In addition, when a user (paid member or not) matches with someone using Carousel, they must spend money to buy coins in order to message the person. SmartPick is equally flawed; Zadeh says the site gets to know you like Netflix, but even after weeks of confining search mode to people in New York City, SmartPick will still set you up with people located in other states entirely.

And yet Zoosk is thriving. At the end of 2013, it was the highest-grossing dating app and among the 25 highest-grossing iPhone apps for the year. With 2.9% market share, according to IBISWorld’s latest report, Zoosk is among the biggest players that sit below the market leaders; Spark Networks (LOV), which owns JDate, is only slightly ahead with 3.1%. Zoosk’s membership is up about 44%, and according to its S-1 filing, revenue went from $109.1 million in 2012 to $178.2 million in 2013, a 63% leap. Its revenues come either from subscription fees or from people purchasing those virtual coins that allow you to message a particular person or use “boost” to be promoted to more people.

Zoosk is not profitable. It posted net losses of $2.6 million in 2013, and under “risk factors” in the S-1, Zoosk discloses, “We have a history of losses, anticipate increasing our operating expenses in the future, and may not achieve or sustain profitability in the future.” The service’s average user is 29, and half of its business is outside the U.S. It is in 80 countries total and has 170 employees.

Chief executive Zadeh, who has an interesting background story — he grew up in Iran, and in 2000, hitchhiked from Iran across the border into Turkey in order to get a visa — says that even though Zoosk is logically painted as a competitor to big dogs like Match and eHarmony, “I would rather look at LinkedIn (LNKD) and Amazon (AMZN) [for influence] than these companies that haven’t changed in years.” His co-founder, Alex Mehr, a friend from college in Iran who also joined him at University of Maryland, where each earned advanced degrees, previously worked at NASA. With Zoosk, which Zadeh says has built up a lot of data on daters’ behaviors, “Our job is to hide the complexity from the customer.”

Once it goes public, Zoosk’s executives will have to do the opposite to stand apart in a crowded market: demonstrate its complexity.