Which directories I back up with SpiderOak

I use SpiderOak to back up two directories on my Linux box: /etc and /home/jon.

Using Disk Usage Analyzer, I identified the following directories as consuming lots of space and not needing to be backed up, so I excluded them from the backup: .cache, .local, .mozilla, .opera, .SpiderOak, .Downloads

Currently my backup requirements are just 20 MB.