This section takes the data from "Referring sites" and sums it up by domain. AWStats does not show this information. If a referer has a link to your site on each of its pages, the overall number of referred visitors might be high, but the referrer might still not show up in the top 10 of the "Refering Sites". This is why BetterAWStats shows the domain sum so you can judge the true value of a refering site.
