The demographics of massive open online course (MOOC) analytics show that the great majority of learners are highly qualified professionals, and not, as originally envisaged, the global community of disadvantaged learners who have no access to good higher education. MOOC pedagogy fits well with the combination of instruction and peer community learning found in most professional development. A UNESCO study therefore set out to test the efficacy of an experimental course for teachers who need but do not receive high-quality continuing professional development, as a way of exploiting what MOOCs can do indirectly to serve disadvantaged students. The course was based on case studies around the world of information and communication technology (ICT) in primary education and was carried out to contribute to the UNESCO "Education For All" goal. It used a co-learning approach to engage the primary teaching community in exploring ways of using ICT in primary education. Course analytics, forums and participant surveys demonstrated that it worked well. The paper concludes by arguing that this technology has the power to tackle the large-scale educational problem of developing the primary-level teachers needed to meet the goal of universal education.