Our thesis is that online, self-directed learning hasn't fully substituted colleges (even though all the content is out there!) because college actually provides great learning environments.
Both paywalls and ads have a range of advantages and disadvantages. Some of these vary by medium: books are expensive enough to print that they couldn't be funded by advertising; an analog radio receiver is simple enough that a paywall would require draconian legal force. On the internet, however, I think ads are generally a better fit for two reas... See more