Sudden surge in spam- I don’t get the end goal…

Check out this screenshot of some examples of polite WebBots leaving me feedback on my Bitcoin Mining Rig post.

 

Some examples of spam left as comments.

Some examples of spam left as comments.

OK so putting aside for a moment the incomprehensible use of the english language here, I don’t get the end goal here at all.  What do these randomly generated comments aim to achieve?  Something SEO related?  I indend to find out.   If you happen to know the answer please leave me a comment :).  Obviously whoever made this spam program does not use english as a first language.