Last spring Sam Fiorella was recruited for a VP position at a large Toronto marketing agency. With 15 years of experience consulting for major brands like AOL, Ford, and Kraft, Fiorella felt confident in his qualifications. But midway through the interview, he was caught off guard when his interviewer asked him for his Klout score. Fiorella hesitated awkwardly before confessing that he had no idea what a Klout score was.

The interviewer pulled up the web page for Klout.com—a service that purports to measure users' online influence on a scale from 1 to 100—and angled the monitor so that Fiorella could see the humbling result for himself: His score was 34. "He cut the interview short pretty soon after that," Fiorella says. Later he learned that he'd been eliminated as a candidate specifically because his Klout score was too low. "They hired a guy whose score was 67."

Partly intrigued, partly scared, Fiorella spent the next six months working feverishly to boost his Klout score, eventually hitting 72. As his score rose, so did the number of job offers and speaking invitations he received. "Fifteen years of accomplishments weren't as important as that score," he says.

Much as Google's search engine attempts to rank the relevance of every web page, Klout—a three-year-old startup based in San Francisco—is on a mission to rank the influence of every person online. Its algorithms comb through social media data: If you have a public account with Twitter, which makes updates available for anyone to read, you have a Klout score, whether you know it or not (unless you actively opt out on Klout's website). You can supplement that score by letting Klout link to harder-to-access accounts, like those on Google+, Facebook, or LinkedIn. The scores are calculated using variables that can include number of followers, frequency of updates, the Klout scores of your friends and followers, and the number of likes, retweets, and shares that your updates receive. High-scoring Klout users can qualify for Klout Perks, free goodies from companies hoping to garner some influential praise.

But even if you have no idea what your Klout score is, there's a chance that it's already affecting your life. At the Palms Casino Resort in Las Vegas last summer, clerks surreptitiously looked up guests' Klout scores as they checked in. Some high scorers received instant room upgrades, sometimes without even being told why. According to Greg Cannon, the Palms' former director of ecommerce, the initiative stirred up tremendous online buzz. He says that before its Klout experiment, the Palms had only the 17th-largest social-networking following among Las Vegas-based hotel-casinos. Afterward, it jumped up to third on Facebook and has one of the highest Klout scores among its peers.

Klout is starting to infiltrate more and more of our everyday transactions. In February, the enterprise-software giant Salesforce.com introduced a service that lets companies monitor the Klout scores of customers who tweet compliments and complaints; those with the highest scores will presumably get swifter, friendlier attention from customer service reps. In March, luxury shopping site Gilt Groupe began offering discounts proportional to a customer's Klout score.

Matt Thomson, Klout's VP of platform, says that a number of major companies—airlines, big-box retailers, hospitality brands—are discussing how best to use Klout scores. Soon, he predicts, people with formidable Klout will board planes earlier, get free access to VIP airport lounges, stay in better hotel rooms, and receive deep discounts from retail stores and flash-sale outlets. "We say to brands that these are the people they should pay attention to most," Thomson says. "How they want to do it is up to them."

Not everyone is thrilled by the thought of a startup using a mysterious, proprietary algorithm to determine what kind of service, shopping discounts, or even job offers we might receive. The web teems with resentful blog posts about Klout, with titles like "Klout Has Gone Too Far," "Why Your Klout Score Is Meaningless," and "Delete Your Klout Profile Now!" Jaron Lanier, the social media skeptic and author of You Are Not a Gadget, hates the idea of Klout. "People's lives are being run by stupid algorithms more and more," Lanier says. "The only ones who escape it are the ones who avoid playing the game at all." Peak outrage was achieved on October 26, when the company tweaked its algorithm and many people's scores suddenly plummeted. To some, the jarring change made the whole concept of Klout seem capricious and meaningless, and they expressed their outrage in tweets, blog posts, and comments on the Klout website. "Not exactly fun having the Internet want to punch me in the face," tweeted Klout CEO Joe Fernandez amid the uproar.

But not everyone wants to clock Fernandez. In fact, he appears to be at the forefront of a new and extremely promising online industry. Klout has received funding (a rumored $30 million of it) from venture capital behemoths like Kleiner Perkins Caufield & Byers and Venrock. It's facing down competitors like Kred and PeerIndex, racing to establish something akin to the Nielsen ratings for online social interactions. Klout may be ridiculed by those who find it obnoxious or silly or both, but it is aiming to become one of the pillars of social media.

All-Star Klout-Off! ——————-

Klout scores are compiled using proprietary algorithms that purport to quantify online influence. Size matters: Large followings on Twitter or Facebook can boost your rating. But it’s more important to have a high percentage of posts that are liked or retweeted. And just interacting with someone who has lots of Klout can jack up your score.—S.S.

Photos: Scoble: AP; Zuckerberg, Conway, Rza: Getty; Corbis

For a guy whose company seems to encourage loudmouthed self-promoters, Fernandez himself is remarkably soft-spoken and self-effacing. When I meet him in Klout's offices, beneath a freeway overpass in San Francisco's South of Market district, he flops down in an armchair, wearing a faded plaid shirt and a pair of raggedy sneakers. His hair is unkempt, his smile goofy, his manner friendly and open. He frequently asserts that Klout has succeeded only because he "hired people much smarter than me."

Fernandez's humility is key to his appeal. "If the CEO of Klout was a type-A guy, I think many of us would take offense when he talks about scoring us or judging us," says David Pakman, a partner at Venrock. "But Joe's not like that. He's uniquely suited to this role."

Fernandez got the idea for Klout in 2007, when at the age of 30 he had surgery to correct a jaw misalignment that had plagued him for years. Doctors wired his jaw shut for three months. "It was mentally and emotionally way tougher than I thought it would be," Fernandez says. "I couldn't talk to anyone. Even my mother couldn't understand what I was saying." He resorted to posting on the still-young Facebook and Twitter as his only means of communication. He posted his opinions on videogames, suggested neighborhoods to check out, and recommended restaurants—even though he wasn't eating solid food. Every time a family member or friend responded to one of his updates, he relished his ability to sway their behavior. And as he looked over his feed he saw countless other people doing the same thing, recommending products or activities to an enthusiastic audience. Fernandez began to envision social media as an unprecedented eruption of opinions and micro-influence, a place where word-of-mouth recommendations—the most valuable kind—could spread farther and faster than ever before.

Fernandez's vision was helped along by a series of biographical confluences. He had studied computer science at the University of Miami, going on to help run a pair of analytics companies—one in education, the other in real estate—that worked with massive, unwieldy streams of information. So he was familiar with the concept of finding patterns and value in large amounts of data. And as the child of a casino executive who specialized in herding rich South American gamblers into comped Caesars Palace suites, Fernandez saw up close and from a young age the power of free perks as a marketing tool.

With his jaw still clamped shut, recovering in his Lower East Side apartment, Fernandez opened an Excel file and began to enter data on everyone he was connected to on Facebook and Twitter: how many followers they had, how often they posted, how often others responded to or retweeted those posts. Some contacts (for instance, his young cousins) had hordes of Facebook friends but seemed to wield little overall influence. Others posted rarely, but their missives were consistently rebroadcast far and wide. He was building an algorithm that measured who sparked the most subsequent online actions. He sorted and re-sorted, weighing various metrics, looking at how they might shape results. Once he'd figured out a few basic principles, Fernandez hired a team of Singaporean coders to flesh out his ideas. Then, realizing the 13-hour time difference would impede their progress, he offshored himself. For four months, he lived in Singapore, sleeping on couches or in his programmers' offices. On Christmas Eve of 2008, back in New York a year after his surgery, Fernandez launched Klout with a single tweet. By September 2009, he'd relocated to San Francisco to be closer to the social networking companies whose data Klout's livelihood depends on. (His first offices were in the same building as Twitter headquarters.)

Fernandez says that he sees Klout as a form of empowerment for the little guy. Large companies have always attempted to woo influential people. It's why starlets get showered with free clothes and athletes get paid to endorse sports drinks. It's also why, once blogging took off, popular scribes like mommy blogger Dooce started receiving free washing machines. But Fernandez says that, until the dawn of social media, there was no way to pinpoint society's hidden influencers. These include friends and family members whose recommendations directly impact our buying decisions, as well as quasi-public figures best known for their Twitter updates—like, say, San Francisco sommelier Rick Bakas, whose 71,000-plus followers hang on his every wine-pairing suggestion. "This is the democratization of influence," says Mark Schaefer, an adjunct marketing professor at Rutgers and author of the book Return on Influence. "Suddenly regular people can carve out a niche by creating content that moves quickly through an engaged network. For brands, that's buzz. And for the first time in history, we can measure it."

Calvin Lee is a graphic designer in Los Angeles with a Klout score of 74. He has received 63 Klout perks, scoring freebies like a Windows phone, an invitation to a VH1 awards show, and a promotional hoodie for the movie Contraband. To keep his score up, Lee tweets up to 45 times a day—an average of one every 32 minutes. "People like food porn," he notes, "so I try to post a lot of pictures of things I eat."

Lee once took a vacation during which he had no access to the Internet. This made him uncomfortable. "I was worried that brands couldn't get in touch with me. It's easy for them to forget about you. And I knew my Klout score would go down if I stopped tweeting for too long." When he was loaned an Audi A8 for a few days as a Klout perk, Lee knew exactly where he wanted to drive it. He road-tripped from LA up to San Francisco, eventually arriving at the Klout offices and shaking hands with Joe Fernandez. Naturally he tweeted and hashtagged the entire journey.

It's easy to understand why marketers would want to reach maniacs like Lee. "We want to create powerful brand advocates," says Tom Norwalk, president and CEO of the Seattle Convention and Visitors Bureau, who arranged a two-day, all-expenses-paid trip for 30 high-Klout visitors. "We hope these folks will tweet and Instagram to their many followers." Virgin America has offered free flights, Capital One has dispensed bonus loyalty points, and Chevrolet has loaned out its new Sonic subcompact for long weekends.

But there's more to the Klout score than a thirst for freebies. Throughout our lives, we are tagged with scores, some of them far more crucial to our well-being than anything Fernandez has handed out. Credit scores are maddeningly opaque and can be used against us in infinitely more harmful ways than a Klout score ever could. Our health records are used by huge organizations to segment and sift us behind closed doors. And yet there is something uniquely infuriating about the Klout score. "They're calculating a Q score for everybody, and it turns out there's a lot of emotion tied up in that," Schaefer says. And the fact that Klout users' status is so explicitly linked to material gain makes it an even more freighted situation, he says. "This is the intersection of self-loathing with brand opportunity."

Almost immediately after Fernandez sent his Christmas Eve tweet debuting Klout—long before there were any perks to win or advantages to gain—the company was deluged with users just curious to see how they measured up. "I didn't think about the ego component of having a number next to your name," Fernandez says. When we see ourselves ranked, "we're trained to want to grow that score."

When I began researching this story, my own score was a mere 31. So I asked Klout product director Chris Makarsky how I might boost it. His first suggestion was to improve the "cadence" of my tweets. (For a moment, I thought he meant I should tweet in iambic pentameter. But he just meant that I should tweet a lot more.) Second, he pushed me to concentrate on one topic instead of spreading myself so thin. Third, he emphasized the importance of developing relationships with high-Klout people who might respond to my tweets, propagate them, and extend my influence to whole new population groups. Finally, he advised me to keep things upbeat. "We find that positive sentiment drives more action than negative," he warned.

Using these tips, I managed to boost my Klout to 46 before it plateaued. From that point, I just couldn't jolt the needle any higher. And, to my sheepish frustration, I wasn't being offered any good perks (which seem to kick in when scores hit 50). It became clear that if I wanted more Klout, I'd need to game the system harder. I could glom on to influential Twitterati and connive to get retweeted by them. I could dramatically accelerate the frequency of my tweets, posting late into the night. And I could commit myself to never taking a break: Makarsky made it clear that a two-week vacation from social media might cause my score to nose-dive. The thought of running on this hamster wheel forever was positively exhausting, and it made me wonder whether Klout was really measuring my influence or just my ability to be relentless, to crowd-please, and to brown-nose. Consider that the only perfect 100 Klout score belongs to Justin Bieber, while President Obama's score is currently at 91. We might not wish to glorify a metric that deems a teen pop star more influential than the leader of the free world.

In the depths of my personal bout with Klout status anxiety, I installed a browser plug-in that allows me to see the Klout scores of everyone in my Twitter feed. At first, I marveled at the folks with scores soaring up into the seventies and eighties. These were the "important" people—big media personalities and pundits with trillions of followers. But after a while I noticed that they seemed stuck in an echo chamber that was swirling with comments about the few headline topics of the social media moment, be it the best zinger at the recent GOP debate or that nutty New York Times story everybody read over the weekend.

Over time, I found my eyes drifting to tweets from folks with the lowest Klout scores. They talked about things nobody else was talking about. Sitcoms in Haiti. Quirky museum exhibits. Strange movie-theater lobby cards from the 1970s. The un-Kloutiest's thoughts, jokes, and bubbles of honest emotion felt rawer, more authentic, and blissfully oblivious to the herd. Like unloved TV shows, these people had low Nielsen ratings—no brand would ever bother to advertise on their channels. And yet, these were the people I paid the most attention to. They were unique and genuine. That may not matter to marketers, and it may not win them much Klout. But it makes them a lot more interesting.

Seth Stevenson (seth@sethstevenson.com) is the author of Grounded: A Down to Earth Journey Around the World.