Database backups are super important. They are also important when you have to do migrations.
Some of the sites can just be deleted and don't need to be migrated so you need only a few databases exported.

Almost all of my business & personal files are in Dropbox so they are backed up as soon as something changes which is nice and I don't have to think about it.

When programming, though, the databases are not automatically backed up to the cloud. There's mysqldump tool but you can either export/dump one or all databases. You have to write a tool for  that.  I checked and there's lots of linux tools that allow you to export the databases which is nice but if you're running Windows they probably won't work.

For those who don't want or can't use linux/bash here's a php version of a mysql database dump tool. It exports each database in own sql file. If gzip is present it will compress it. If there are errors they are logged in a database specific log file.

You can download the php version of MySQL database dump here:
>> https://github.com/orbisius/server-tools/raw/master/mysql_db_dumper.php

If you want to contribute to the project feel free to fork it at
>> https://github.com/orbisius/server-tools