I had yet another blog spammer's visit. This is interesting and shows how creative techniques they use.
First, it was a comment spam. Two entries (more than 6 months old) were affected. For someone who's not looking at ALL the comments, it'd be hard to spot.
The spam started to appear when there was a gap between the entries. When I posted a new entry, it stopped. This behaviour has reasons. When blog is not visited by the author it's a 'good' idea to spam it. Better profits. Taking the number of abandoned blogs...
IPs -- different. Looks like a botnet or something similar.
Time between posts. That's interesting. One and a half to eight hours. I guess it has something to do with the ranking system that says 'modified -- good, but modified too often -- bad'.