Here's something that I haven't seen before, so I don't even know if there's a term for it. I'll call it "Comments Spam".
It works like this: a person leaves a one-word entry in a blog's Comments section, something like "Cool!" or "Neat!", but the URL they enter for their homepage is not their own blog but instead where you'd go if you click any of the links in the e-mail Spam messages that clog your inbox. It's a pretty sneaky way to guarantee I'll look, since I wager most bloggers -- except the really big ones -- tend to check out those URLs when a unknown person leaves a comment.
I got two of these the other day. One of them linked to some credit-card offering site, and the other actually did lead to a BlogSpot blog. But the blog in question only had one post on the front page, and it only had two permalinks in its sidebar, one of which led to the exact same ad site as before. My first thought -- "Hey, a new reader!" -- was immediately replaced by irritation. (Which makes me wonder just when "Irritate your potential customer as early on as possible" became good sales advice.)
On the off chance that I'm wrong, and this wasn't some new wrinkle in foisting advertising on those who don't want it, I merely deleted the comments in question. If this continues, though, I will ban any users who try to leave such links in my comments.
I don't get too worked up about spam in my e-mail; mostly I just delete it en masse. Ditto pop-ups; I don't get offended by them as long as I can close them easily. Mostly I just let them sit there on my screen until I'm done doing Web-stuff entirely, and then I close all current IE windows. But this new thing, if it is a new thing and not just a one-time anomaly, will annoy me greatly.