I want to like Mongo, I'm all about "cutting my teeth on the bleeding edge", but I don't know what to think about MongoDB. Most conversations about it seem to go like this:

Lover: MongoDB is so much faster and easier than old school SQL! Hater: It's fast and easy because it doesn't check if it's written data correctly, which leads to corrupt data. Lover: Well you could always turn on the write lock. Hater: If you turn on the write lock, it becomes slower than normal SQL databases. Lover: Well you're just trying to use it the same way you use SQL. MongoDB is great for some problems and not so great for other problems. Hater: What problems is MongoDB better at solving?

And then that's the end. I've never heard a convincing use case for this thing. If you can change that for me and give me one, I'd be delighted to listen.