At Georgia Tech we got a very small server space which was used in a few CS classes, it would have been large enough to run hubot. Your university might have a similar setup.
Heroku was basically becoming the go-to place to run thousands of little bots—and more importantly, to advise people to run their little bots—without thinking about marginal costs. It was becoming everyone's little pocket of persistent personal cloud agents. The "launch on Heroku" button on Github pages was a thing you could just press on a whim as a realistic solution to your problem.
