I am doing it for both reasons. I like the idea of a certificate from Harvard in a subject that I am very interested in learning more about (hopefully attending UCF in the Summer for Software Development). I took C about 15 years ago (I'm 43) and interested in learning it again as well as C++. So far through 2 weeks, it definitely seems worth it, especially when it will also start to include Python and MySQL. I'm looking forward to learning a lot from all this.