Freud and road construction

I’ve just been checking back on an old post, one relating to a quote by Sigmund Freud, in which he uses the phrase: de mortuis nil nisi bonum (speak nothing but good of the dead). Curiously this particular post attracted not one but four comments that were plainly nothing but advertising. (I’m loathe to block comments on my site because I get so few of them!). The first three were all from the same crowd advertising road construction (yup, it has everything to do with Freud, and/or speaking good of the dead). The fourth comment was for some other equally unrelated item. I’ve just deleted all four (which reduces my comment rate considerably, no doubt), but I’d still love to know why they turned up on this post in the first place!