We used to "do-follow" links on comments from this blog.
On some blogging platforms, you can disable this feature. By providing inbound links to your commenters, you help them with their SEO rank, thus encouraging and rewarding comments. That is "do-follow".
Why did we stop following?
We're still fans of the do-follow movement, but the quantity and deviousness of the spam just got to be too annoying.
Yes, we run Akismet and other anti-spam plugins. The bad guys are too clever and persistent.
While the tingle of my first corollary is still fresh (Alan’s Corollary to Clarke’s Third Law), I'll postulate another.
Anything that can be spammed, will.
--Alan's Marketing Corollary to the 2nd Law of Thermodynamics
(That couldn't be original, but I didn't find the phrase on Google...)
Just as universe runs downhill towards increasing entropy and disorder, so do spammers destroy all free mass communication channels.
Email is the prime example, of course. CNet reports 95% of all email in 2007 was spam. Insane.
But also spam is also harming natural search. Blog comments. And increasingly, spammers are spreading their muck across the social web.
The only channels immune from devolving into the entropic gray goo of spam are those which require payment (for example, paid seach) and those which are "pull" media (for example, RSS).
Anyway, we're no longer "following" on this blog. Sorry a few bad apples ruined it for everyone else.