According to Akismet, 90% of all blog comments are spam.
The Live Spam Zeitgeist says:
Totals
Total spam: 39,640,978
Total ham: 4,167,699
Today (UTC, 17 hours left)
Spam today: 643,205
Ham today: 10,528
And here’s the reason why we’re getting a barrage of comment/trackback spam lately.
Google should buy Akismet. :p
So that’s why spam TBs were getting through. Hmmm…I wonder what would happen if Google indeed buys Akismet?