Alexa's certified program and pro metrics.
http://www.alexa.com/siteowners/certify
Analytics and Tracking · Audience Measurement · Visitor Count Tracking
Get access to data on 282,271 websites Alexa Certified Site Metrics Customers. We know of 21,353 live websites using Alexa Certified Site Metrics and an additional 260,918 sites that used Alexa Certified Site Metrics historically and 7,576 websites in the United States.
Get a list of 282,271 websites using Alexa Certified Site Metrics which includes location information, hosting data, contact details, 21,353 currently live websites and an additional 44,983 domains that redirect to sites in this list. 260,918 sites that used this technology previouslyand 7,576 websites in the United States currently using Alexa Certified Site Metrics.
Countries
Financial
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Region
These are sites that we think might use Alexa Certified Site Metrics in the future because of their similarity to other sites that already do.