In the fall of 2007, the number of students registering for 3.091 reached 570 students, over half the freshman class. The largest lecture hall available on campus seats 566 students, enough to amply house the class. Sadoway much preferred teaching in one of the smaller lecture halls, seating only 450; as such, the Institute had to take the unprecedented step of streaming digital video of the lecture into an overflow room to accommodate all the students interested in taking the course. In contrast, most classes at MIT are relatively small with approximately 60% of classes at MIT having fewer than 20 students. The popularity of this course has reached outside of the MIT campus as a result of the MIT OpenCourseWare initiative. This is seen in a comment by Bill Gates who told the Seattle Post-Intelligencer "... Everybody should watch chemistry lectures -- they're far better than you think. Don Sadoway, MIT -- best chemistry lessons anywhere. Unbelievable".