One of the things associated with learning something new is deciding what level of mastery to achieve. Do I aspire to speak Spanish well enough for a vacation or do I want to speak fluently with specialists in finance and banking?
Coursera lets you adopt your level of mastery without any kind of social stigma based on other people judging you. It’s way more autonomy than a F2F class, where I am pretty sure it will not be good for my reputation to be seen getting a “B” or worse. In the world of online learning, no one will think less of me for just watching the lectures and absorbing some of the key ideas – I decide what I need.
When I’m going for credentials, I take the tests and try to meet the standards to a high degree – but when I’m just trying to learn something useful, I’d like to decide how far to go. When learning comes in smaller chunks (6 weeks instead of 16), it’s a lot easier to schedule into my life. I believe I could get a masters degree in this way, whereas making the commitment to semester-long courses is hard for me to maintain, given the conflicts with my regular job.