It's a web 1.0 thing. https://en.wikipedia.org/wiki/Webring

this was a popular one: https://en.wikipedia.org/wiki/Ate_my_balls

Webrings kinda went away when "blogging" became the new thing, and then there were blogrolls and pingbacks and delicio.us and whathaveyou. That got supplanted by the larger glurge into social media with friendster, then myspaces top 8, and now everyone is just on facebook saying "what's the point?".

Indeed. As mentioned, its for personal sites as a lightweight way to share a link to a friends site that may or may not be related, rather than a list of affiliates or sponsors or whatever.