Massive Open Online Courses (MOOCs) have opened the halls of higher education to learners around the world, with prestigious universities vying to share their educational riches and project their brands into new territory. A precursor was Massachusetts Institute of Technology’s decision in 2001 to share its syllabi online. The rush accelerated after more than 100,000 people signed up for a free artificial intelligence class that Stanford University professors offered in 2011.

Today rival companies offer courses taught by professors from Harvard, Princeton, and the University of Michigan as well as the National University of Singapore, McGill, Australian National University, ETH Zurich (Swiss Federal Institute of Technology), and dozens more. Coursera and Udacity are for-profit "start-ups" funded by venture capitalists banking on an eventual payoff from their million-dollar investments. Rival edX is nonprofit, but was started with $60 million from Harvard and MIT.

One route to profitability and sustainability is to charge for extra attention, certificates of completion, or actual credits. Most MOOCs now feature only machine-graded, multiple-choice quizzes, or papers graded not by faculty but fellow students, who may be encouraged to form their own study groups and meet in coffee shops in hometowns from Dallas to Delft to Delhi.

The fly in the MOOC ointment is that while eager learners sign up by the tens of thousands, very few do the work. A 5 percent completion rate is par for these courses. Many who sign up are college-educated adults pursuing personal enrichment or simply following their curiosity, not impoverished, teenage strivers in countries with narrow pathways to higher education.

University of Pennsylvania education researchers who tracked 1 million users who signed up for Penn’s 17 Coursera courses in 2012–2013 found only half viewed at least one lecture. Still, the Penn offerings attracted more than 40,000 people from China and India alone.

China has a half-billion Internet users and MOOCs are so popular that some of the country’s biggest entertainment websites such as 163.com, sina.com, and yyets.com provide links to MOOCs alongside celebrity news. Some have organized volunteers to translate English language lectures.

Jingfeng Xia, an associate professor of library and information science at Indiana University-Purdue University Indianapolis who studied this phenomenon, found a Yale course on Fundamentals of Physics was viewed 1.9 million times on 163.com and a Harvard Positive Psychology course attracted nearly 2,200 comments, many of them expressions of gratitude.

"They are dedicated learners. They are working very hard on their MOOCs," said Xia. He quoted one college senior’s post: "Open courses open a window for us to sit inside top universities of the world. It’s like fresh air that makes people revived."

The reach of MOOCs is growing. In Jordan, Queen Rania Al Abdullah’s foundation has launched Edraak.org, an Arab language portal for MOOCs built on the edX platform. "Edraak will open up a world of possibility for intellectually hungry Arab youth," she said in November.

Although questions remain about how to sustain MOOCs, online education already was burgeoning on U.S. campuses thanks to vast improvements in technology and access to high-speed connections, said Kenneth Green, director of the Campus Computing Project.

Green, writing in Trusteeship, the Association of Governing Boards’ magazine, noted that colleges have long harnessed new technology to reach wider audiences, from extension courses on radio in the 1920s and 1930s to CBS’s "Sunrise Semester" on television in the 1950s. But Green cautioned, "MOOCs do not, at present, offer a quick and easy path to new revenues."

Still, with people watching lectures on YouTube and iPhones, MOOCs give universities new opportunities to meet their often expressed missions of service to the world.

A decade after opening shop, the 2,200 courses on MIT’s OpenCourseWare website draw 1 million visitors each month. After logging a combined 100 million visits, MIT has set a new goal: one billion by 2021.

This article originally appeared in the May/June 2014 issue of International Educator magazine.