I love hearing from former students about the great and interesting things that they’re up to—and especially when something they learned in one of my classes helped them along the way. In my experience, former students who are up to great and interesting things would often be doing those things whether or not they had taken one of my classes, but I still appreciate feeling like my teaching contributed in some small way.

Yesterday, I complained about Apple putting artificial limitations on what its hardware and software can do in terms of music syncing in order to make more money out of its consumers (and, probably, keep music companies happy). As I was writing that, I was thinking about similarities with the business model of a lot of mobile apps—let people download the app for free, but keep bonus features (or even the best features) behind a paywall.