For example, someone posted something on comment 3 that either is appreciated or detested, another person can cut in right below that person's comment and either praise or blast them.
Blog dicking is especially fantastic when a drama meltdown breaks on someone's topic. People will be blog dicking left and right to tell the offender how much they suck. AMAZING!
So a blog dicker will reply to the first commenter on the first page of comments so that EVERYONE can see their comment. Usually blog dicking is self promotion on someone else's blog. They reply to someone's comment but it has nothing to do with the comment they responded to.
Blog dicking is not replying to someone's comment, even if it just happens to be near the top of the first comments, if you really are responding to what they have commented about. But sometimes people make it look like they are relying to someone's comment when really they are blog dicking by adding something like: Hey come visit my blog it's better!
I hate blog dicking.