Domain typos are the common mistakes that people make while trying to insert a website, by registering the popular typos you can protect your brands and visitors and redirect them to your main website.
Certified Site Metrics are metrics that are directly-measured from the website instead of estimated.
The "Sites Linking In" count shows the number of sites that Alexa found that link to this site.
Daily Pageviews per Visitor Estimated daily unique pageviews per visitor on the site.
These metrics have a greater level of accuracy, no matter what the ranking.