There are three forms of link building to date : 1) One-Way Link Building; 2) Two-Way Link Building; 3) Three-Way Link Building. Most search engines crawl a website and save all outgoing links found in there. Then they will check if these links link back to the website. If so, then a two-way link exchange (or reciprocal linking) exists. If not, then a one-way link exists giving more credit to the referred site of the hyperlinked term.

One-Way Link Building

One-way link building is the most ideal form of link building. This will boost the website’s authority for relevance in a particular word or phrase. This can be illustrated briefly as one website term (also called keyword) is being hyperlinked to another target website which describes more about the keyword.

In this way, greater link influence is being credited to website B than website A for such a particular keyword. Ideally, website B is expected to be talking more about the keyword than what website A describes about it.

Two-Way Link Building

Also called reciprocal linking, two-way link building is one of the easiest ways to gain links to other websites. In this way, there exists a correspondence between two websites linking back to each other for each other’s keyword. For example, if website A links ‘keyword1’ to website B, then website B in return would be linking ‘keyword2’ to website A as shown in the following :

Two-way link building is often discouraged when keyword1 is just the same as keyword2 because this would mean search engine algorithm would likely to distribute link influence of the target keyword to both. When both keywords are also closely related, it is also highly probable that the two website would obtain lesser link influence to each other’s keyword. Thus, two-way link building should be minimized as possible to prevent one website to referring to other websites about keywords of interest.

Three-Way Link Building

Three-way link building is uncommonly utilized link building form because it needs three website linking to each other each one having a unique keyword. The following illustration shows how three-way link building can be constructed with three webmasters linking to one other with no reciprocal linking exists in any two of them :

This shows that all three websites get their share of full link influence when their corresponding target keyword is highly unrelated. Furthermore, this form of link building appears to be a one-way link building between website A referring keyword1 to website B, between website B referring keyword2 to website C, and between website C referring keyword3 to website A. Each site boosts its authority for the keyword it is being referred.