I am sure you have got bloggers putting irrelevant comments in your posts plus links to their sites. I will show what I do when I get such comment spam.
1. I set comments to only registered users (meaning they must have a Blogger account)
2. I moderate comments, and thus have a permanent record of the comments in my Inbox together with the spammer blogger profile.
2. I use Yahoo email address to receive comment moderation email notification and set the option to display full header (giving details of IP addresses, etc).
To set Yahoo to display full header, click "Options", "General Preferences", then in the "Messages" section, tick the radio button beside "Show all headers on incoming messages"
3. Highlight all the information the the header and copy to clipboard.
4. When I get a comment spam, click the down arrow in "Forward" and select "As Inline Text", type "Reporting comment spam. Full header:" then paste the full header into the message.
5. Add "Reporting comment spam" in front of the message subject
6 Forward to email@example.com
Amazon products on spam
I have done this a few times, and hope Blogger support have the time and/or willingness to stamp this spamming out. However, I have not received any feedback from them after reporting comment spam. However, I have reported email spam to firstname.lastname@example.org, email@example.com, firstname.lastname@example.org and have got positive responses.
If you are using Gmail, to get the full header, at the top right of the page, click the down arrow beside "Reply" and chose "Show original" and the full header will be displayed. See screenshot below: