The 5-foot-7-inch Jacksonville Jaguars running back Maurice Jones-Drew earned the nickname "Pocket Hercules" for his bruising running style, but the diminutive chatterbox can't seem to take a verbal hit.

Addressing listeners on his Sirius XM fantasy football program, Runnin' With MJD, just before the NFL season began, he groused about his middling fantasy draft prospects. "A lot of people are out there saying, 'Can he come back on that knee? Can he do what he did in '09?'" Jones-Drew said. "A lot of fantasy football gurus who've never stepped on the field before or been in a locker room, they seem to know best."

How far the game has come. Once a cultish pursuit of stat nerds, over the past decade fantasy football has grown into a sport with some 27 million players, including athletes themselves. Along with the office drones who consider themselves devotees are A-list actors, politicians, and captains of industry. (One exclusive league populated by a number of hedge fund titans competes for a $1 million cash prize.)

Americans spend an estimated $800 million per year on all fantasy sports media products and services, according to the market research firm Ipsos. (Out of that, football gets a majority of the money, as 71 percent of fantasy players follow that sport.) Add subscriptions to platforms indirectly related–such as DirecTV's NFL Sunday Ticket, NFL's RedZone, and Sirius XM's MLB packages–and the total market impact, says the Fantasy Sports Trade Association, is now nearly $5 billion per year.

Indeed, the big winners are not so much the players, but online media companies. They're generating revenue not only through league fees, online paywalls, and, of course, "traditional" ad buys–some 80 percent of the portals are ad-supported–but through new and creative ad opportunities that are helping point the way for websites feeling hemmed in by banners and video pre-rolls.

For the uninitiated, fantasy football is a game of stat sheets and schadenfreude. Participants join leagues, of which there are countless nationwide (some informal among friends; others formalized and often costing minimal fees). Exact rules vary, but, in general, each person drafts position players, as well as a defensive unit and placekicker. Points are generated by the stats put up every week by the selected NFL players, and the teams that end the regular season with the best records advance to the postseason.

The rise of the Internet has helped fantasy football expand exponentially from its start as a sort of cabalistic exercise in mathematics and obsessive fandom in the late '90s, when Yahoo Sports and CBS SportsLine.com launched their first fantasy products. "The growth of fantasy football aligned very nicely with the growth in broadband," says David Geller, head of Yahoo Fantasy Sports.

"The Internet is responsible for three pandemics," adds one digital buyer. "Porn, gambling, and fantasy. And there's honest money to be made in the latter."

A great deal of real-time, statistical minutia is needed to staff and maintain a competitive roster, which is why many of the dollars generated by fantasy football accrue to online sites that offer complimentary access to live scoring, updates, injury reports, and projections. Advertisers looking to stake their claim in the arena can spread their marketing dollars across a host of less-trafficked sites like Fantasy Sports Ventures' KFFL.com and TheBigLead.com, or belly up with the big boys at CBSSports.com, Yahoo Sports, ESPN.com, and NFL.com. At these bigger websites, according to media buyers, fantasy buys can range from $750,000 for real estate on high-traffic data and news pages to $3 million for a full-season presenting sponsorship.

Some sites let players dabble for free, but make them spend for expert advice and specialized tools, like draft analyzers. ESPN.com, for instance, locks much of its advice behind its Insider paywall, which offers exclusive content at prices ranging from $30 to more than $70 per year. And to ensure there's a bundle, online subscribers also get ESPN The Magazine, a biweekly print publication. It also offers a mobile app for $4.99.

Dave Coletti, vp of digital media research and analytics at ESPN, says certain in-house usage patterns led to Bristol taking a closer look at the correlation between mobile and fantasy usage. (Coletti is active in three leagues, one of which is made up of his fellow ESPN researchers.) "That's one of our platforms that benefits from the explosion in fantasy sports," he notes. "People don't go anywhere without their phones, and it's become almost the default option for news and data. The last two Sundays in September, we had 10 million people using our ESPN mobile service, and much of that traffic was fantasy driven."

The uptick in mobile usage has had a concomitant lift on the digital side of the ledger. Season to date, ESPN's fantasy football users are up 19 percent from the prior-year period, says Coletti. The site garnered more than 100 million page views in the first month of the season, accounting for nearly half of all traffic.

Coletti has other numbers to tout as well. As a sidelight of Bristol's ongoing ESPN XP (cross-platform) initiative, the network has begun layering digital research over Nielsen's ratings data, and found that "our fantasy football players watch 25 percent more Monday Night Football than the typical viewer," says Coletti. "These are loyal and engaged fans, two words advertisers really like to hear."

CBSSports.com makes most of its money by charging for its fantasy football modules. A league pass on CBSSports costs $179.99 per season, while individual player subscriptions vary based on the potential final payout. But despite the cost of entry, business is booming. Ten years ago, the site–then known as CBS SportsLine–took in $4.3 million in fantasy subscription revenue; this year, analysts expect it to surpass the $50 million mark.

Advertisers, and not just car brands, are coughing up for the fantasy experience. This year, once it became apparent that a full season of NFL action was in the cards, marketers flooded the zone. Two weeks after the lockout ended on July 25, CBSSports.com sold out the last available inventory on its fantasy football pages, signing Sprint, Subway, and Volkswagen as lead sponsors.

Volkswagen's deal, which is for three years, secures the exclusive automotive sponsorship of the site's fantasy football offering. The marketer is using its affiliation with the site as a means to showcase the 2012 Passat, the midsize sedan featured in the "mini-Darth Vader" spot that aired during the second quarter of Super Bowl XLV.

Yahoo Sports–which enlisted more than 4 million fantasy football players, up 15 percent from a year ago–also enjoyed an accelerated pregame sales period, lining up full-season commitments from the likes of Pizza Hut, Visa, Toyota, and Miller Lite.

In addition to offering the usual ad buys, portals that deal in fantasy sports are letting their imaginations run wild. Normally, a website has a finite amount of ad space to sell. But fantasy games are expanding the parameters by attaching value to the reams of available minutia. These executions allow media outlets to maximize placement without overwhelming the user with sponsor messaging.

ESPN.com, for example, has GMC's Never Say Never Award, given to the team able to pull out a last-minute win by the smallest margin. Yahoo Sports has a Biggest Blowout Award sponsored by Toyota, which also backs its "Hall of Fame" staging area–where users can post photos of their league trophies and talk smack–and its Medal Leaders tally, which rewards individual players for game-day performance.

"Some of the sites go a little overboard," says one digital buyer. "It's like, 'This space where you can talk shit to your buddies is brought to you by Geico. The top five QBs of the week are brought to you by Pizza Hut.' But when it's just one or two lead sponsors, it's less intrusive. It's like seeing a [linear] Chevy spot four times in a quarter . . . repetition eliminates clutter."

Not surprisingly, NFL broadcasts are becoming laden with real-time fantasy stat updates. There are now even two cable TV programs devoted exclusively to fantasy sports: ESPN2's 90-minute The Fantasy Show, which averaged 1.2 million viewers on Oct. 23; and NFL Net's midnight show, which drew 166,000 viewers on Oct. 20.

As fantasy continues to grow it has helped engender a new breed of football fan. A New York Giants fanatic, say, might not draft Eli Manning because he always looks like he's afraid there are monsters under his bed, so he or she takes San Diego Chargers QB Philip Rivers. Before fantasy, you wouldn't think of staying up late to watch two iffy AFC West teams lock horns on Monday Night Football. Now, there's no such thing as a blowoff game. You stay up for the Chargers-Chiefs game because you need to see your starting signal caller put points on the board. As a bonus, you can text that buddy who picked Kansas City's Jamaal Charles in the draft to remind him that he's down a starting running back.

That (anti)social element helps make fantasy football so engaging to so many. And it's what inspired Jeff Schaffer and Jackie Marcus Schaffer to create the FX comedy The League. Less a send-up of fantasy football than an indictment of human nature in general, its central thesis is that everyone secretly hates his or her friends and revels in tormenting them. The show basically uses fantasy sports as a framing device for a host of petty animosities and sexual peccadilloes.

"We wanted to do a show about people who've been friends forever, and yet are enthusiastically horrible to each other," says Jeff Schaffer. "Fantasy football is a perfect medium for that, because one of the main reasons people play is it gives them an opportunity to humiliate one friend for the enjoyment of the rest of the group. If you treated a stranger the way you treat your fantasy football friends, you'd be put in jail."

The Schaffers play in a fantasy league with the six principal cast members, and the standings reflect an emerging segment in fantasy sports. "I won our league last year," says Jackie Marcus Schaffer. "Katie [Aselton], who plays Jenny on our show, won the first year. So, yeah, we're doing OK for ourselves."

While the FSTA estimates that male players account for as much as 75 percent of the fantasy football base, women are increasingly buckling their chin straps. Last season, female viewers made up 33 percent of NBC's Sunday Night Football deliveries; moreover, 46 percent of the 111 million Americans who tuned in to Super Bowl XLV were women.

"There's this prevailing notion that fantasy is played by a bunch of sports wonks crunching the numbers on their Excel sheets, but we're increasingly seeing that football is becoming part of the zeitgeist," says Yahoo Sports' Geller. "It's a bit like during March Madness when everyone in the office joins the NCAA pool. Technology democratizes the fun."

While fantasy football has helped pump millions of dollars into the media space, the phenomenon is only as sound as the NFL itself. Faced with the prospect of a lost NFL season, Fantasy Football Index in July scrapped its annual draft guide. The company estimates it lost half of its annual revenue as a result.

ESPN The Magazine also put the kibosh on its annual fantasy football guide. The Boston-based media consultant Pohly Company estimated that ESPN may have lost as much as $4 million in ad revenue as a result.

As for the professional athletes who have climbed aboard the fantasy football juggernaut, the game doesn't always reward self-confidence. Maurice Jones-Drew may regret choosing himself in the first round of this year's draft; through the first eight games of the season, he's ranked ninth among running backs, scoring 100.5 fantasy points on three touchdowns. Fantasy sites are labeling Jones-Drew something of a bust, although some analysts believe he'll find the end zone in the latter half of the season. Sometimes the self-proclaimed "gurus" do know more than the pros.