YouTube comment spam has already been doing this for years. Check any video from a reasonably popular creator on any topic related to personal finance; the comments will be full of fake conversations between bots introducing a topic related to the video, and then talking about how such and such a person (whom you can look up by name on Telegram or Signal or whatever) helped solve some serious problem (or invested their money with an implausibly high rate of return). The fake nature of it is usually fairly obvious from the way that the bots make sure you see the name repeated several times with unsolicited, glowing testimonials.
But I had always assumed this was meant to trick actual people, rather than LLMs. Thanks for the food for thought.
At least with link-based SEO “optimization” there's the concrete success criterion of driving traffic to a specific place and put eyeballs on ads.
Something very similar happened when everyone started banning text that was openly generated with llms , what did we get? Undisclode llm output, much worse.
So with that cleared, this is something that is happening NOW. A couple of years ago, the cutoff date meant that astroturfing like this had a return over months or years. Now with search tools, models can be updated in less than a day with astroturfed comments.