It's well worth doing, especially if you have an important series of events to chronicle. I started my original blog in the late 90s: I wrote the software myself (probably badly) and based it on PHP and MySQL: I thought other bloggers at the time did that as well.. maybe they didn't :) Anyway, I chronicled the first 5 years of my new family growing up, complete with pictures, and diligently backed up the precious database on a regular basis, to CD. Then, after moving house a couple of times I realised that I'd physically lost the F**** backup, and my blog was lost forever. I never quite got over that. Nowadays it wouldn't be a problem with multiple backups to Cloud etc. If you're going to start a blog on any platform, make sure you back it up!