Maybe nothing. I didn't look into other options because Tarsnap is already cheaper than a cup of coffee per month and it's run by someone I trust and want to support.

I'm with you on that it's cheap and also run by someone trustworthy. However, what happens if he decides to retire or something similar? At least S3 is almost surely going to be around.

If he disappears and suddenly my backups aren't available. Then I'll start backing up somewhere else. No biggie.

If he disappears, suddenly my backups aren't available, AND my drive blows up, all at the same time, then I'll be sorry I guess.