[chubot]

Honest question: where do Postgres and MySQL fall down for such deployments? What is the administration required? Backups? Users and permissions? Indices?

FWIW I use sqlite for a personal wiki, i.e. a website with exactly one user :)

[codefined]

I think the idea is that if your service does more, it necessarily needs more work to maintain. From a simple point of view, there are just more moving parts to go wrong.