Online Audience Data Affected by Methods

A study from the US Online Publishers Association (OPA) has found that different methods of compiling online audience figures lead to significantly different estimates of visitors to local web sites. The research is based on an analysis of measurement tools from Nielsen//Net Ratings, comScore, Scarborough and The Media Audit.

The OPA analysed data for both local and national web site visits for three different local markets - Los Angeles, Orlando and Kansas City. Data was provided by comScore Media Metrix, Nielsen//NetRatings' MegaView Local and @Plan products, Scarborough Research and The Media Audit.

The ComScore and Nielsen//NetRatings MegaView Local services use panel-based methods, whereby software installed on individuals' machines records all the web sites visited. The Media Audit, Scarborough, and Nielsen's @Plan product, on the other hand, use telephone surveys of audiences, using both aided and unaided recall of sites visited

The OPA found that the survey-based services reported about 70% more visitors to local sites than the tools that use panels. There are considerable variations behind this average figure: in Los Angeles, for example, The Media Audit estimated local visitors to LATimes.com at about 1.5 million, while comScore reported roughly just 0.5 million.

The differences between methods were much smaller for national web sites. On average, the OPA found that tools using survey methods reported about 10% fewer visitors to national sites than those using panel methods.

While the estimated number of visitors reported varied widely between the services, the relative ranking of sites across methods and vendors was generally consistent.

The OPA's President, Michael Zimbalist, explains that locally-targeted ad spending is increasing rapidly as the use of local web sites expands. He hopes the research will marketers 'evaluate the various services more objectively'.

Full details of the research are in the Local Audience Measurement White Paper, written by Marissa Gluck, Founder and Managing Partner of Radar Research. The paper is online at www.online-publishers.org.

All articles 2006-23 written and edited by Mel Crowther and/or Nick Thomas, 2024- by Nick Thomas, unless otherwise stated.

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