There is some sort of wink wink nudge nudge agreement going on with certain spam accounts. You will see them post article spam with hidden history, and if you look up their posts either via google or any other reddit crawling tool, they are posting all over various subreddits that same article maybe dozens of times. If they comment it is really basic and formulaic and found all over their post histories as well.

I feel like reddit enjoys it as these posts (often political in some way) usually get good engagement which is in line with reddits own incentives for courting advertiser money.