I buy domain names for weird and random ideas that come to me. I really like the reverse concept of buying interesting domain names and then letting them turn into something that you never anticipated. That sounds like a really fun and potentially highly rewarding hobby. It also seems to break every Startup book's rules, since you're looking for a problem to a solution, but who cares? This guy is having tons of fun and learning a lot, so good for him.

Edit: Looks like they have some competition: https://www.vidaliaonion.org