This past Thursday (March 1, 2007) seems to be a bit of an anomaly. I say this because overall message volume is the lowest it has been since New Year's day. Ignoring that holiday, it's the lowest it has been since early October. Compared to February 28, traffic is down 37%.
That seems a little weird. It's almost as if a big group of spammers decided to simultaneously go on vacation or stop spamming. Perhaps they are starting to collude together.