What is the 3 way linking ?

[AlyLauren]

Some webmasters own multiple sites and try to build up one of their specific sites by offering link exchanges from their other sites. In doing this they add a link to you on their other site and get you to link to the main site they are trying to build up.

try reading some blog post regarding 3way linking on search engine land, you will surely get informative and latest update.