National governments, local regulators, taxi companies, direct competitors. All are out to stop Uber or at least slow it down. Some of its own drivers have filed a class-action lawsuit against the company.
But according to details from a leaked document published Friday by Reuters wire service, Uber is a global force. Total ride-share bookings are showing explosive growth, from $688 million in 2013 to a projected $10.84 billion this year and $26.12 billion next. That's nearly 38 times bigger in just four years.
These are the most detailed numbers on Uber bookings to find wide public distribution.
They come from a presentation apparently used by Uber in its latest round of funding, according to Reuters. Thus far, the company has raised $7 billion from private investors for an imputed market valuation of more than $50 billion.
Uber takes about 20% of driver bookings and counts that as revenue. Arithmetic would roughly put its 2015 revenue at $2 billion.
Another gem found in the presentation: Uber contemplates a public stock offering in 18 to 24 months. That news kicked off another flurry of speculation about whether the company is generating earnings.
When reached for comment, an Uber spokesperson said the company does not comment on rumor and speculation.
"I think what's really interesting is whether they're profitable yet," said Hugh Tallents, a partner at management consulting company Cg42.
The answer: It's almost certainly not. Uber's heavy upfront investments are all part of the "punch" approach that Thilo Koslowski, vice president and automotive practice leader at research firm Gartner, says Uber has employed from its very beginning in 2010. It punches itself into markets and spends big on advance teams, lawyers and lobbyists to fight opposition and gain a foothold in markets around the world.
Previous document leaks — sketchier than the latest — have shown Uber losing money, as many young companies do as they aggressively grow.
Uber is more aggressive than most. The ride-hailing service currently operates in more than 60 countries. In the U.S., you can hail an Uber in more than 150 cities. The company recently said it plans to spend $1 billion in China and another $1 billion in India to grow its business. Chief Executive Travis Kalanack said he expects the China market to exceed the market in the United States.
That's got some observers worried.
"When everyone has the Uber app, every driver is using Uber, and everyone is connected through Uber, there's going to be no room for anyone else to start a dispatching service," said Evan Rawley, associate professor at Columbia Business School.
At that point, the company can increase its rates and reduce its spending on subsidies.
"It's bargain-then-rip-off pricing," Rawley said. "Classic network effect."
Still, Uber faces stiff competition in India and China, where one ride-hailing company, Didi Kuaidi, is partly financed by China's sovereign wealth fund.
In Europe and South Korea, the company faces regulatory battles over the legality of its service, with Spain and France banning the service because Uber's drivers don't carry the required permits to operate commercial vehicles.
In the States, the company is facing a class-action lawsuit over worker misclassification.
Despite these hurdles, Uber remains bullish.
Koslowski said the numbers in the presentation seem "a little too high" and are probably on the top end of the company's projections, but he said he didn't doubt Uber had the potential to pull in such revenues.
"This is a gold mine for Uber," Koslowski said. "That's why the company is getting so much funding from investors. It's no secret they make a lot of revenue, we just don't know what's left after their spending. Once the spending is reduced, these revenues will turn into profits."
Then there are the opportunities Uber hasn't even talked much about. Steve Sarracino of growth equity firm Activant said the company is currently in the business of transporting people, but its own business model is paving the way for ancillary services such as the pick up and delivery of physical goods, the transportation of workers and, potentially, optimizing traffic flow. The company is also developing self-driving cars.
Sarracino believes that of all the multibillion-dollar tech companies to have emerged over the last 10 years, "Uber is most likely to challenge Google [at] providing game-changing technology," he said. "Uber has a dominant core product that … will provide cash flow to invest in adjacent products and markets. Not even Facebook or Amazon will have this type of flexibility because they lack adequate cash flow."
As for whether the company could go public within the next two years as the investor presentation forecasts, Koslowski said the San Francisco company could go public, but that doesn't mean it should.
"It doesn't seem like they have any problems securing funding and investment, and really, you want to [have an] IPO to expand your base to get more funding," he said. "I don't think the company needs that at this point."
Analysts believe that Uber has given them plenty of reason to feel confident about the company, even if its profit margins are currently unclear.
Uber's expansion, for example, shows no sign of slowing down. Its transformation into a household name also spells good things for the brand.
"It's easy to forget Uber is a colloquialism now," Tallents said. "It's easy to forget the company is not even 6 years old."