Wow, axe to grind or what? You have three comments on here all belittling something that many people find perfectly acceptable and successful in production. Of all the non-SQL choices, Mongo isn't a terrible one. We've got (along with many other companies) 300gb in Mongo and it's been loads more enjoyable to use in a replica set than MySQL has been in a master/slave architecture, and every bit as reliable. More so if you count the simple live failover that just works.

It's a data model that works very very well for some datasets. We use MySQL for stuff that is obviously relational, but we store a bunch of geo data as JSON for fast serving to javascript etc. It's a perfect fit.

But seriously, if you don't have a backup of any of your data stores, that's a big problem.