Manchester United isn’t a soccer teamat least not in the business sense.

The Cayman Islands holding company that owns one of the world’s most popular sports franchises registered this week to go public on the New York Stock Exchange. As its filing with the Securities and Exchange Commission shows, the company is an advertising-dependent content producer that enjoys strong brand visibility and loyalty. In other words, it’s in the media business.

This could make the idea of Manchester United going public feel a little less alien to investors in the U.S., where private ownership of sports teams is nearly universal. (Remember the great Cleveland Indians IPO of 1998? Didn’t think so.) At the same time, investors haven’t been especially kind to media-themed IPOs over the past year.

Manchester United brought in nearly 60 percent of its 2011 revenuealmost $300 millionthrough traditional media company channels: selling access to content and selling ads tied to that content. The company brought in more than $180 million by selling broadcasting rights to the team’s matches and more than $85 million in corporate sponsorships and tie-ins. New media and mobile accounted for another $27 million. The rest of the money comes from ticket sales ($172 million) and team-branded merchandise ($48.6 million).

Each of those revenue streams rises or falls depending on the power of the Manchester United brand, which itself rises or falls depending on how well the team plays. Historically, it has played legendarily well. But fans have complained that Man U’s ability to compete for top players has suffered since taking on massive debt in U.S. businessman Malcolm Glazer’s $1.5 billion leveraged buyout of the team in 2005. The $100 million the team hopes to raise in the IPO will go to pay down its debt, which totaled about $657 million as of March 31.

“That’s not exactly what the market really loves,” Georgetown University finance professor Reena Aggarwal said of the team’s red ink.

Nor does it like debt-ridden sports teams going up against ultra-rich guys who focus on winning first, and what it costs second. In its SEC filing, Manchester United says competition for top players has become intense as billionaire sheiks and Russian oligarchs add soccer teams to their personal portfolios: “Recent investment from wealthy team owners has led to teams with deep financial backing that are able to acquire top players and coaching staff, which could result in improved performance from those teams.”

That dependence on a few key players to underwrite a company’s entire brand raises Manchester United’s risk profile, which could lead to a bumpy ride for its shares, Aggarwal says. “It’s not a diversified business,” she says. “It’s a very concentrated kind of business.”

Like Facebook and Google, Manchester United’s IPO will create preferred shares that will give the owners greater voting power than ordinary shareholders, which like Mark Zuckerberg will let Glazer keep control over his company even after the public gets a piece of it.

And also like Facebook, and every other social media company that has tested the public markets recently, Manchester United is pinning its appeal to investors on its ability to monetize the 659 million “followers” it claims to have worldwide. Facebook boasted of more than 800 million users in its IPO filing, but so far they haven’t helped its share price. Nor have big user bases done much for Yelp, Zynga or Angie’s List shares either since they went public within the past year. And Google’s returns have been mediocre during the same period.

Certainly, Manchester United, Google, Facebook and every other Internet darling aren’t in the exact same business, but they do have similarities. They all monetize eyeballs, sell ads, and are competing for people’s time by offering some form of content/entertainment or in Google’s case, services. For investors to sink their money into it, Man U needs to prove it can consistently hold people’s attention, not just in the competition with other sports teams, but in the competition with all your friends’ Facebook photos.

Maybe investors will like that they can see Manchester United’s players on the field and their frenzied fans waving red in the stands. There’s a concreteness to a sports team even if like other media companies most of its money comes from selling experiences and cachet tied to its brand, rather than a physical good. Aggarwal says the same intensity that fans bring to the team could also lead them to buy the stock.

But sports dynasties seldom last forever. In soccer as in Silicon Valley, a team that can’t keep up with its rivals quickly loses its fan base. Those fans might take defeat even less well when a missed Wayne Rooney shot means they also lose their shirts.