You can limit the size of your report by filtering by the websites traffic rank. We provide traffic ranking data as supplied by Quantcast and Alexa which both run to 1m and should be considerd as US focused. The lower the ranking, the more traffic that site has, 1 = google.com for example.
You can set either or both the rankings when creating a report. The “Preset” option includes entries like “Sites in the top 100k” and fills out the Start/End options for you.
If you don’t use the Traffic Rank filtering system you will get all sites using the technology.