As a related data point, I had a post go viral today on Google+ (~500 +1s, 100 shares) [1] and after about an hour, the most inane comments started piling on.
"hello"
"hi friendz"
"hi"
"Every one how is the day?"
"What's the topic for today, can any one tell me? Please!"
etc etc
I can explain the timing. It presumably hit "What's Hot" so they all saw it. But like OP, I don't know what to make of it. Maybe one of the OP's theories, maybe all of them.
These comments doesn't make sense for spam (unless their account links to a lot of spam?) I wonder if it's non-english speakers trying to practice their english.
Without squinting too closely, I think it's this one. I get these on Livejournal and have seen them around the 'net. There's generic content that may apply to any possible post, and then the incentive is the PageRank that flows back from the username link. An improvement even would be to have a bot generate text based on the post, and then have paid humans deal with the captchas. </evilhat>
hhmmm ... not sure, seems they are really bad in English (e.g. "JuuuuubtghyAujkykkik").
Some are obvious spam or I guess she just want's to meet guys:
"hello"
"hi friendz"
"hi"
"Every one how is the day?"
"What's the topic for today, can any one tell me? Please!" etc etc
I can explain the timing. It presumably hit "What's Hot" so they all saw it. But like OP, I don't know what to make of it. Maybe one of the OP's theories, maybe all of them.
1. https://plus.google.com/106413090159067280619/posts/ZFTKZQfj...