There are a lot of subreddits which routinely award hundreds or thousands of upvotes for repetitive low value posts. … This is a cog in the well-tuned machine of new-accounts being created and matured to look ‘real’ for when they are later used for advertising / manipulation later down the line.

In the early months of a new account, it is easier to spot. Eg. If you see a post on a game subreddit with a title like “Exciting to try this game, any tips get started?”, you might click the profile and see that their entire history is a bunch of low-effort discussion starters. “Name a band from the 80s that everyone has forgotten”; “What’s the most misunderstood concept in maths?”; “What’s the most underrated (movie / band / drug / car / tourist attraction / whatever suits the topic of the subreddit)?”

A heap of threads like that, on a new account with a very generic name (adjective-noun-numbers is a common pattern); posting on a variety of subredits… is highly suspicious. But it gets harder to recognise as the account gets older and has a longer history - at which point it is ready to be sold / used for its next purpose.