I've been spreading a collection of about 20 links to mostly mainstream media articles which discuss shills. If you haven't seen it, take a look.

I don't doubt that you are at least somewhat correct. If there is money to be made somewhere, someone will find a way to obtain it. However, I would be extremely surprised if we somehow proved that shills either aren't on Reddit, or they have a very small presence.

Shills might not actually be posting content to smallish subs like /r/conspiracy. But, if any one of many corporations and governments paid just one guy with some handy software, they could control what all 300,000 subscribers see on their front page. Only about 500 people actually participate in that sub in the comments sections, as you can see by looking at the sidebar. And upvoting a shitpost to the top, or burying a few good posts wouldn't take very long at all, so this one shill is free to perform another 7.5 hours of work elsewhere on Reddit or otherwise. It would be stupid to not hire that shill because it is so cost effective.

Now, when we are looking at massive subreddits, you can see why this is almost inevitable that shills will be present. I've personally seen weird threads in /r/worldnews where the first, second, and third comment all appear to be coming from the same person, usually having a very pro-Israel/US position. How do I know it's the same person? Because A) at least two of the accounts post maybe once a month, the third perhaps being a primary account. B) all 3 only post in /r/worldnews. And C) One of our conspiracy members went through the histories of all 3 and matched specific grammatical errors, spellings of words, and the like, making it very unlikely that all 3 accounts are separate people. What this means is that at least one shilling company has the resources to tailor the content and votes on a massive thread to their liking, which should be scary.