There are many great questions facing the ambitious search engine optimisation practitioner. Very few webmasters have spent long in the game without considering the potential for link exchange schemes to improve their website rankings. But the question is: is it worth the risk?
It should come as no surprise that search engine operators are not too keen on the idea of indiscriminate link exchange schemes. This prejudice is rooted deep in the underlying principles upon which search engines rely for their continued success. In particular, search engines use the concept of PageRank to determine the relative authority of websites - PageRank is calculated based on the quality and quantity of inbound links to a particular site. Entering into a link exchange agreement can make the PageRank of your website less accurate as an indicator of the quality of your content. It goes against the basic web premise that a link can be counted as an editorial 'vote of confidence' for the content at the link destination.
Link exchange schemes were far more popular in the early days of the web than they are today. This is partly because the algorithmic methods used by search engines to discover and penalise websites that engage in link exchange schemes have become more effective over time. As webmasters began to realise that the performance of their websites was suffering as a result of these schemes, the schemes became less popular.
Despite these disadvantages, link exchange schemes are sometimes considered a viable shortcut to search engine results page ranking gains. On a small scale, there is nothing wrong with a link exchange that develops a legitimate relationship between related websites. For example, if a media business that publishes an ezine about cheese decides to exchange links with a website that sells a rare and divisive type of cheese, no harm is done to the overall user experience and visitors to either website stand to gain from the transaction. By contrast, a large-scale and indiscriminate link exchange agreement is never a good idea.
Search engine operators penalise the participants in link exchange agreements wherever they are discovered. These penalties could take the form of a ranking filter penalty that causes a given website to appear lower in the search engine results, or in prolific cases, complete de-indexing by the search engine operator concerned.
Ultimately, link exchange schemes are often fairly easy for search engine operators to detect and penalise. Websites that engage in such schemes rarely survive long without experiencing negative effects, and penalties can be severe. Although some types of link exchange scheme are more subtle and difficult to detect than others, it is always best to take a more organic approach to link building - focus on creating high-quality content for your own website (and perhaps the websites of others). This is the best route to ranking gains and search engine success. For businesses that lack the writing talent and technical know-how to achieve this without help, there are many third-party organisations that specialise in providing these services.