Web Rings are an additional way to generate qualified web traffic.
Essentially (if well managed) a web ring is a collection of similiar-minded sites that "come together" in the one place on the web.
The theory is this...
If a person is looking for information on a particular topic then when they come across a web ring on a particular topic they're more likely to click through to another site in the same locale, if it's in the general topic area they're searching for information on.
Web rings can create a traffic "loop"...meaning that visitors to your site can click through to the web ring you're involved with (and thus give traffic to others) OR visitors can come into the ring from another site participating in the ring, and then click through to your site. This is traffic you otherwise would not have got.
The most important thing with web rings is to...
Be theme-focused when you join a ring. Think of it like this. "If you go to the supermarket, and you want bread you don't go looking for it in the dairy section do you?"
Look at the other sites participating in the web ring. If they're theme related it means that the traffic will be focused.
Look at the traffic count. Is this ring getting traffic? What's the point of joining a web ring that's not getting any traffic, and is also unfocused?
Note: However (with this being said) it can be valuable to join a low-traffic, highly focused web ring. Especially if it's just started and appears to be well managed. Focused traffic is extremely valuable.
Consider starting your own theme-focused web ring.
Below, you'll find a wide selection of netBIZ-focused web rings...