Accounts that will likely get big offers will have a large number of followers, mod large subreddits or targeted subreddits.
Having an active account before the 2016 Russia thing is also worth something. When you want to spread misinformation or do shill marketing, it helps a lot to see any of the following when checking a user's Reddit profile:
- the user didn't register a month ago.
- the user didn't register just to talk exclusively on this subject/product.
- the user registered before Russia's IRA became active on Reddit.
- the user didn't stop exclusively participating in porn or sports subreddits just to make this comment.
- the user is writing enough quality comments that they don't feel compelled to delete most, if not all, of them.
- the user is not making contradictory claims (there is a famous example of someone claiming to be a cis woman in computers who had clearly cis male comments in several cis male oriented subreddits, one of them called something like "semen rentension". They were called out.
- the user posts in subreddits that are on good terms with the subreddit we found their suspicious comment in.
Source: I'm a Reddit moderator and work at a marketing startup.
There’s no easy way to identify comments on the Internet as stolen, so with enough dedication it’ll be possible to create a system that generate profiles with years worth of life by just mishmashing elements. That will help bots pass spam filter developer on top of existing filter itself.
Subs can limit posts to users with some minimal karma or age. Typically this still permits comment, though harvesting comment karma is then incentivised.
Automoderator, a rule-driven automated moderation tool, can actively interact with posts and comments based on various criteria, including automatically holding or removing posts or comments, messaging submitters, and other actions. This is heavily used on highly-active subs, and pretty well documented.