Site explorer allows you to inspect certain aspects of a URL. The Inlinks feature shows you details about web pages that link back to the particular URL you are exploring. Site Explorer gives you some insights on how popular a website is based on how many web pages are linking to it.
Compete is a web-based analytics tools that allows you to compare the traffic statistics and trends of up to three websites. It gives you an estimate of how many unique visitors and page impressions a website gets and how fast a website is growing in popularity
Quantcast is another popular site traffic measuring tool. Quantcast allows publishers to Quantify their website â€“ a process in which you place a script in your web pages so that they can measure your traffic statistics directly. With that said â€“ sites that arent quantified may not have accurate/complete data and many people arent comfortable about placing third-party scripts on their websites.
Started in 1996, Alexa is the most popular traffic ranking service today. It tracks traffic statistics of websites and provides a numerical rank based on the data that they collect. You can find a websites Page Views and Reach (the % of internet users that have visited the website)
An effective way to determine a websites popularity is by tracking its RSS feed subscriber trends. If a website uses FeedBurner â€“ the leading provider of RSS feeds services â€“ you can use Feed Compare to see trends in subscribership from websites and compare growth/decline of subscribers for up to 4 feeds at one time.
popuri.us is a tool that can help determine how popular a URL is based on web services and statistics such as Alexa, Technorati, Delicious bookmarks, number of subscribers, and more. Its a one page tool that gives you a quick overview of how popular a website is. popuri.us even gives you the option to post a widget on your site to display your popularity.
socialmeter is a web tool that scans how popular a web page is throughout major social websites such as Digg, Stumbleupon, and Delicious. It gives you a socialmeter score which is currently just a summation of the results found (useful for comparing social media website popularity of different websites).