I’ve been noticing a sharp upturn in comment spam including bizarre references to gmail servers, such as www2-2.gmail.com and I can’t figure out what’s up.

The comments are archetypical spam comments, but the message, instead of containing links to products, contains several similar links to gmail servers. I generally still shoot on sight, but I’m curious what the purpose is. If any of you have been leaving comments like that, take the time to explain why, please?