I think false positives on spam are a significant problem for Wikipedia, but false negatives are also a significant problem (maybe a bigger one), which is part

I think false positives on spam are a significant problem for Wikipedia, but false negatives are also a significant problem (maybe a bigger one), which is part of what makes it tough. If you hit "random article" a bunch of times, look for biographies on currently living people of relatively low levels of importance. I would estimate about 20% of those are clearly puff pieces, either written by a PR agency, a university/company publicity department, the person themselves, someone they know well, etc. It's not the end of the world since those articles also tend to be not that frequently read (articles on high-profile people are much harder for a PR agency to control the content of), but it does make me take Wikipedia somewhat less seriously when such a large proportion of random pages I land on are obviously written by a PR hack, using the kind of diction you expect to find in a press release or an official university bio, rather than language you would expect to find in a respectable encyclopedia. While bios are the biggest area, there's a bunch of other areas where I've learned not to pay attention to Wikipedia because it's too spammy: anything to do with tourism (full of booster and hotel spam), any company except very high-profile ones, many non-profit organizations, etc. It's good when writing about people/things that no longer exist, though; the articles about 19th-century French companies don't read like they were written by a PR agency.