What is three way linking..?
Three way link building is the link exchange among three domain instead of two.
Most people engaging in 3 way link exchanges are doing it with the express intent to manipulate search results. This typically means they are trying to make automated bots think their ideas are better than they are, and are willing to do deceptive things to do it.
A few website admins claim different destinations and attempt to develop one of their particular locales by offering join trades from their different destinations. In doing this they include a connection to you their other site and motivate you to connection to the primary site they are endeavoring to develop.