According to an article in Fast Company, a spin-off from the University of Nebraska's Division of Continuing studies, class.com, is making a success of offering e-learning to students at approximately 4,200 high schools around the country.

It's an interesting article though it doesn't offer much detail about how class.com's success might be measured.

In addition, the impression is that its ongoing strategy for success assumes infinitely expanding time on the teachers part (let's add more students, expand the time they can expect you to respond to them, emphasize as much personal contact as they want, constantly restructure the course), no stress and/or an unending supply of non-burned out eager young teachers to replace the ones used up in the previous round of classes. E-learning done this way may work for the students, though the findings aren't yet conclusive, but we will need to develop a system that works for both teachers and students if we want it to be sustainable.