When you have been running a web site for some you may start to consider how your hard work is performing in terms of attracting new visitors and retaining existing site visitors. A common way of checking web site reach and popularity is to see how it compares to other sites using a ranking service. Last year I wrote a short article about one such service, Alexa – traffic ranking, and its popularity shows that ranking systems play an important part in the search and search optimisation world. However, a number of additional services are becoming popular offering all manner of methods for identifying, assessing and measuring web sites and their performance, including free and paid for services from service providers such as Quarkbase, Compete, Quantcast, Technorati, Google Trends and comScore.

Keyword and Tag searching are useful (keywords or tags or both) techniques, used by search engines, for collecting and assessing information about the content of a web page for appropriateness to search terms. But, how can a search engine deem the effectiveness or authority of one particular site over another. One way would be by assessing the visitors who visit a site, how often they visit, their time on the site, and how often other websites refer back (link back) to a web page contained on the site. These are referred to as site metrics.

Citing references is a common, and expected, technique in the academic world and in a similar way back linking and one-way linking are techniques which have made their way over into popular web site culture – many modern search engines use back-linking, especially one-way linking, as a method for assessing a website authority. One-way linking is where site A links to a web page on site B without site B including a link to site A in return. Over time, a number of these techniques have been combined into a useful technique by search engines so that when a user conducts a search the results returned are based on both authority and appropriateness.