Alexa provides free information about sites, including statistics, related Links, keywords driving trafftic to a site, and more. All of this information can be found on Alexa's Site Info pages. Just type the URL of any site into the Alexa search box and click the "Search" button.
Compete.com provides traffic volume estimates and site analytics to all the top websites. It is the only online competitive intelligence service that combines site, search and referral analytics in a single product and user interface to help you quickly master online marketing.
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