Sometimes I come across an expression and then check how popular it is by googling it. If it’s very popular, it’s highly likely that the expression is a strong collocation although there are many exceptions of course. And then there is the rare occasion where the expression looks as if coined by a native speaker. “Insidious shilling” is such a case.
I was totally baffled by this until I realized that shilling was not the coin, but the actions of a shill.
The UrbanDictionay gives an updated definition of shill as:
“A person engaged in covert advertising. The shill attempts to spread buzz by personally endorsing the product in public forums with the pretense of sincerity, when in fact he is being paid for his services.”
I’ve never heard the term “insidious shilling”, but now it makes sense.
Yes, I found the expression on Medium in the following contexts:
“Sorry for insidiously shilling my observations and opinions. You dropped your tinfoil hat by the way.”
and: “Yes. This kind of insidious shilling is starting to become common on Medium.” So, it’s actually two slightly different version: insidiously shilling and insidious shilling.