According to Rosental Calmon Alves, the first edition was the first MOOC about journalism ever organized in the world. It was also an unexpected success: Mr. Cairo conceived it as a little experiment at first, hoping to attract just a few hundred people. He ended up with 2,000 in the first edition, and 5,000 in the second one, coming from more than 100 countries.
Mr. Cairo had also assumed that a course that focuses on how to communicate with charts, maps, and diagrams —and not so much on how to use them to analyze data— would appeal mainly to journalists and designers. This assumption was wrong. Students came from several scientific disciplines, statistics, cartography, education, business intelligence, etc. This variety of backgrounds —professional and cultural— enlivened the discussions a lot.
Here you have an excerpt from the introduction to the third edition:
“Previous experience in information graphics and visualization is not needed to take this course. With the readings, video lectures and tutorials available, participants will acquire enough skills to start producing compelling, simple infographics almost immediately. Participants can expect to spend 4-6 hours per week on the course. Although the MOOC was initially conceived with journalists and designers in mind, others are welcome as well and can benefit from the very practical skills that will be taught.”