I think that anti-astroturf systems are definitely one of the things that should qualify to remain as proprietary data of the people who run the servers.

Much the same as the best online payment processing anti-fraud services are an opaque black box that you feed some data into, and you get a result back. They don't tell you what's going on inside the black box.

I would not be surprised at all if the top vendors for online payment processing fraud detection also offer services for anti-sockpuppet/anti-inauthentic user detection. Some of the methods going on in the back end to analyze the validity of a transaction will also apply.

Considering the modern weaponization of social media to manipulate stocks, elections, protests and such, I would consider that sort of SaaS to be a growth market.