SharePoint Viewers allows you to see the names of people that viewed something. It is activated under Settings > Site Information > View All Site Settings > Manage Site Features.

It also specifies that site members can see who’s viewed.

However, this is not the case. Site visitors can also see who’s viewed the item.

While we are all for promoting transparency on the intranet, this might make your eye twitch depending on the content you want to manage. The setting is not configurable, it’s either on or off. When hovering over content, the viewers block pops up to tell you who’s viewed. This is however useful for people who want to make sure people have read stuff, although probably more suited to smaller audiences. It wouldn’t be easy to audit 2000 viewers as it goes by date order, not alphabetically. Regardless, just remember that visitors to the site can also see who viewed items.