When I returned from my vacation, I realized there were 30 comments in my blog waiting for approval. Some were very easy to recognize as spam. But other looked naturally on the first read. Until I found that it is not probable that english reader would enjoy czech written story.
Then there were comments to my english written story. They looked fine, but author had URL containg commercial keywords (louis vuiton, ray bean, social stocks ..) – I marked them as spam as well. Finally there were few remaining comments, where I had to open author URL and guess, if they were posted by person or spam software. Thank you for your comments, I like them. Sorry if I was wrong and removed your real comment.
I will have to spend some time and search for better wordpress comments solution. Facebook comments might be safe against spammers but I do not want to limit my readers that do not use it. The current solution is too weak, some captcha filter is unfortunatelly neccessary.
PS very nice web spam description