Traffic. I commented ona news story about a woman from my dojo who when getting robbed, chased down and beat up the teenage male youth. Apparently the 53 year old women told the reporters: "he had no cardio, it was easy.". That story got me more traffic than anything else.
Conversation & Comments. When I was a candidate, I would return from our sessions and write up how the session went. I often included pictures. All my classmates would apparently go home and check out my write-up about the killer sessions and add their own comments.
Generally Useful & long term traffic generators - I've put up videos and write-ups of our katas. My school is part of a chain of about ten (five in upstate NY, five in Florida). These materials are often used by students to help learn the kata.
My favorite. My favorite of my posts is one about Why I Blog. Nobody else has much cared about the post but I frequently reread it and think about it.