Alexa Ranking and Google PageRank are probably the two most well known methods of measuring the importance and popularity of a website. There are others as well who have joined the fray, read - Yahoo Backlinks and SEOmozPageStrength, but Alexa Ranking and Google PageRank remain the most commonly accepted web metrics methods.

The Amazon.com owned Alexa has taken steps for reworking their ranking system, and broaden the monitoring of the webmaster influenced toolbar market. An explanation from Alexa in this regard was:

In recent months, we have been hearing from our users that understanding (the pattern of) Internet usage beyond Alexa Toolbar users was increasingly of interest to them. We listened to your suggestions, and we believe that our new rankings system is much closer to what you have asked for. We now aggregate data from multiple sources to give you a much better indication of web site popularity among the entire population of Internet users.

Alexa’s new ranking system offers:

• More sources to give a better indicator of a web site’s popularity
• Better rankings owing to new and improved algorithms
• Improved methodology so that they provide consistently accurate rankings for all countries.