I’ve been a user of Akismet right from when it was in Beta and running under a completely different name – it is so good I can’t imagine turning it off. I’m surprised, though, that spammers don’t take the threat of being blacklisted more seriously. I know I’d be seriously pissed off if I hired someone to promote my site and they got me banned!
On any given day I can check the forums over at digitalpoint.com and find spammers galore. When they get deleted vBulletin sends all their info (IP, message content) out to Akismet and it gets registered. If they do it often enough then they end up in our moderation queue. The mods also have tools to seek and destroy frequent offenders but that’s another story 🙂
Now some spammers, like the cookie stuffers, use throwaway domains so a ban is inconsequential but others are real sites where the misguided owner has handed the company’s online reputation over to the wrong people. They won’t know until its too late that the link building strategy of their “SEO Professional” was seriously flawed.
I’d be really interested in feedback from anyone who has tried to have their site un-blacklisted.