If someone wants to start a blog, and they'd like the content they publish to stick around on the internet for as long as possible into the future, what are their best options?

Buying a domain is tricky because domain names expire

GitHub Pages is pretty great, because GitHub is free and has, to-date, a great track record of not breaking *.github.io content

What are other great options? WordPress.com I think are good on this front

I don't trust anyone with less than 10 years of track record

@simon I'm still at "buy a domain". It's pretty cheap, and all the respectable registrars will remind you when it's expiring, so hard to lose by accident.
@timbray @simon you can also combine the two strategies and host your domain name off of GitHub. I've been doing this for years now and am quite pleased with it.