Boosting impressions to maintain "passive income" is one possibility.

I’ve seen niche forums in the past insert affiliate links, so when somebody clicks on that HP graphing calculator they go straight to Amazon and the site operator gets a 2% commission. This was the approach of a website that plagiarized Obscure Sorrows and was discussed here on HN (https://news.ycombinator.com/item?id=48611823).

And then there’s tinfoil hat territory: massive influence operations that span multiple forums and Wikipedia and random blogs to support specific points of view about scientific claims, preferred technology approaches tied to commercial platforms, and even historical claims such as who or what developed a scientific concept.