There are data sources that are difficult or expensive to obtain but provide a more accurate gauge of web traffic. For example, ad networks can provide this. Yo

There are data sources that are difficult or expensive to obtain but provide a more accurate gauge of web traffic. For example, ad networks can provide this. You can dig deeper and get a representative sample of data from sources such as the OpenDNS Investigate platform. It's a cool product, but the market fit isn't perfect yet.