With the latest batch of additions today, I'm now tracking over 50 different blacklist zones for the newly revamped DNSBL Resource Blacklist Statistics Center. Thinking back to when I created the RRSS blacklist (the Radparker Relay Spam Stopper) in 1999, I am not sure there were even fifty anti-spam blacklist filters across the entire globe. Mine was definitely not the first, but I suspect that RRSS was probably one of the first ten.
Right now, I've got 13-week charts showing the effectiveness of 21 different blacklist zones. Look for public stats on additional lists soon, as I slowly compile effectiveness data on the lists I've just added. (And I've got even more tricks up my sleeve, so stay tuned!)