In my opinion rather without free Statement of Accomplishment many users will likely not return to the site. It might be different in the US, but in Germany there is a culture of "certificate or it did not happen". I have heard that the same holds in Brazil, too. Thus being German I stopped attending Coursera courses as soon as free Statements of Accomplishment were dropped. I also have the impression that after this step the quality of courses dropped.
Originally I remember that it was seriously considered that as a way of monetizing MOOC sites there was the thought that MOOC participants are people that love to learn new stuff on their own. This is something many employers like. So the idea for monetizing was: why not allow employers give (for money) access to the list of participants to find potential employees. Does anybody know why this route to monetizing MOOCs was left?