14 DAY TRIAL // The importance of information contained in a certain website pages is measured by its popularity related to the average number of Internet users that reach the respective website in a given time range. The indicator of a website popularity is represented by the traffic details or reports. The web traffic reports can be obtained by using server log files (for detailed reports) or existing web services.
If you do not know already about the existence of Alexa - the Web Information Company, it provides a web based service of websites popularity measurement through a unique ranking system.
From the beginning of the service existence, the ranking system was based on the analysis of traffic data resulted from Internet surfing by people, using Alexa toolbar. The traffic rank value for a given website correlated with the percent of global Internet users who visited the respective site will reflect the respective website popularity: a lower traffic rank value will indicate a website more popular than one characterized by a higher traffic rank value.
From the general statistics theory and practice, it is known that the most relevant value for a measurement result in case of fluctuating data is the average value. For Alexa web service, the average traffic rank values for one week and respectively three months are presented alongside the corresponding percent of global Internet users that reach a certain website. By comparing a daily traffic rank value (which is also provided) with the average traffic rank, you will get an accurate information regarding the relative website popularity (the relative character is given by the origin selected for comparison such as, for example, all ranked websites or a single website).
Recently, Alexa changed the ranking system by taking into consideration more sources of data and implementing a new ranking algorithm in order to provide a better correlation between the traffic rank and website popularity. As a consequence, if your traffic rank had changed on Alexa, you should not be surprised. Due to the fact that Alexa toolbar reflects only a certain type of information limited to its users, the new ranking algorithm "should better reflect the interests and surfing habits of the broader population of Web users." (Alexa)