We all know about the comment spambots and how they offer us endless access to Russian sexual stimulants and Nigerian bank accounts. Well in an early effort to stem some of that I turned off all 'open access' to comments on any post older than 5 days. I did this ages ago.
So if you comment on a post older than 5 days, your comments get emailed to me and I have to approve them before they're posted. And since I have a life (no really) it sometimes takes a little while for me to get to the approval - they happen very often at about 5:00 AM the next day.
Also, if you comment as Anonymous (you know who you are but we obviously don't) then there is a non zero probability that the system will mistakenly think you are a spambot and send your worthwhile insight to the great virtual abyss even if the post is not 5 days old yet.
So the moral of this story is two things:
1. Sign up with Blogger (a tentacle of google) and comment with some quirky pseudonym. Dubiously awarded Hawaiian warrior names and vaguely Tolkien-esque sounding proper nouns are both popular.
2. Be patient on any comment for a post older than 5 days.