Block spam or report it?

Personally, I don’t block spam. I keep receiving it because I find it interesting to study.

Where does it come from? Single IP? Single domain? Botnet?
Who does it target? list of harvested emails or specifically targeted?
Is it sent aggressively? Hundreds per minute or a few per hour?
What is it about? Meds? Gambling? Porn? Business deals? Visit a site?
Fake sender? valid or just random username with legit domain?
Fake subject? Trying to avoid spam detection?
Small body? Long body? With random chars to avoid checksum checking?
Imagespam? Distorted image?
Sent by professional spammers or amateur (Greek) marketers? :>

After all this, I always report is upstream using Spamcop (HabuL add-on).