I'm rather skeptical, because I've found Postgres to be pretty simple to run on a project of this size as well. Takes like 10 minutes to install it. Maybe bump it up to 30 minutes if you want to do something a little tricky with user accounts, like run the web server with a DB account that has limited permissions, which SQLite can't do at all anyways.

On the small projects, DB admin doesn't seem to be much more complex than using a SQLite DB. By the time you get the DB load high enough that you really want to pay attention to administrating it, SQLite has probably given up the ghost long ago.

Don't get me wrong, SQLite is great for what it does. I don't see the upside to it on this though. Even if you know for sure your site will never hit high traffic, it just isn't that hard to run a conventional DB. And if it does, it's a lot easier to pay somebody to set up your DB server right than to convert over to a conventional DB and then get it set up right.