Spam Trolls.

When you get a comment on your blog that has nothing to do with anything and they're trying to sell stuff, deleting the post isn't enough.
In Blogger, go to the Help menu and type in Spam. All you do is cut and paste the url of the Spam Troll then hit the Submit button.
Blogger will review that url for possible violation of terms. 
And to my readers, I do appreciate the good comments you have given me over the years.
All the best - Liz