• August 13, 2008

ComScore said Tuesday that it will begin providing two sets of measures for online ad networks--one reflecting the "potential" audience reach, and the other showing "actual" reach.

The potential reach will be the total number of unduplicated visitors to all sites that each ad network has contracted to deliver advertising to. In other words, this calculation shows the largest potential audience a network could deliver if all parts of the network are used to deliver ads.

Potential reach calculations will be based on written documentation and confirmation provided by the networks.

The actual figure will represent the reach of ads actually served by the network during a given reporting period. To report actual reach, networks must provide comScore with identification protocols for rendered ads. As such, only participating networks will be included in the actual reach report.

ComScore recently downgraded the ranking of online video ad network YuMe in its Ad Focus report after initially crediting YuMe with 138 million unique visitors in June. The ratings service said it had inappropriately assigned traffic from MSN to YuMe, which had inflated its traffic and ranking. YuMe disputed the revision, saying the original comScore figures reflected the network's full potential audience.

The new ad network metrics will debut with comScore's Augusta data and be released in mid-September.--Mark Walsh