On the other hand, our databases are pretty far reaching and should have hit on even older blog spam domains, yet they largely didn't.
Another thing to keep in mind is that blog-comment spammers don't have the option to go back and rework their old comment with a fresh domain names. We already know that e-mail spammers switch to newer domains all the time to beat the filters, otherwise they would get blacklisted too easily.
This highlights a significant difference in the nature of blog spam and e-mail spam which needs to be taken into account when comparing blog spam to SURBL... (but this difference doesn't mean that they are different spammers.)
Another related question is, do blog-comment spammers ALSO try to avoid old domains names, or do they not even worry about this because of not having to deal with as sophisticated and mature of a spam-blocking infrastructure as the e-mail spammers deal with? Follow?
Rob McEwen