When I was a kid, this was Spam:
Even if you've never eaten it, you might have seen the famous Monty Python video.
Nowadays, it seems this is spam:
SSDN Technologies seem to be my biggest fans - they just won't stop posting spam comments.
I've asked them to stop - they never appear to you guys anyway, as I moderate all comments first (for exactly this reason).
SSDN ignore my emails, and when I tweeted them they just blocked me - charming eh?
They're not alone of course - plenty of SEO companies and other training companies try too.