After a bit of a break in this blog, I did some analytics and much to my surprise I found we were ranking highest for Fake LV Handbags. That was a bit of a shock as we talk about technical translation, so I did some research and realized that a lot of spammers include some kind of link in otherwise ordinary looking comments on my posts.
So I went through and found that virtually all the "great post!" type comments were actually just spammy link building. I deleted all comments and I've set the system to let me review them regularly. If comments look suspicious in future I'll just block them.
It's probably something a lot of people who run smaller blogs need to look out for. Not the worlds hardest lesson, but still something to learn from.