US— Web audience researcher ComScore has criticised the server-centric measurement methodology of its rival Quantcast, which it says is unable to accurately count individual users.

In a newly published paper, ComScore sets out what it sees as the shortcomings in the methodology behind the free services provided by its competitor. It says that Quantcast’s technique, through which participating publishers attach ‘tags’ to their web pages to allow impressions to be counted, is unable to account for the many users who delete cookies from their web browsers, or share computers with other people.

ComScore also raised questions about the transparency surrounding Quantcast’s use of third-party data to provide demographic information.

The seven-page paper on ‘Why panels are essential to counting people’ consists of a lengthy critique of Quantcast’s methods, and a shorter defence of ComScore’s own panel-based ‘hybrid’ approach, which it says comes closer to measuring real people rather than just browsers or computers.

The firm points to the Interactive Advertising Bureau’s audience reach measurement guidelines, which state that any measure of unique users must incorporate data that is “attributable directly to a person”.

Quantcast, which was set up in 2006 and currently provides audience measurement tools for free, claims that its server-centric approach is better suited to the fragmented world of digital media than panel-centric methodologies such as that used by ComScore, which struggle to provide reliable results for sites with smaller audiences.

Speaking to Research, Quantcast’s chief marketing officer Adam Gerber responded to ComScore’s claims about the company’s openness regarding its use of demographic data, saying: “Our methodology documentation provides very clear descriptions of how our data is collected, modelled and inferred… We leverage multiple sample-based reference points as part of our unique inference model, and the agreements we have in place with them do not allow us to name them.”

Quantcast’s tools were developed with the specific aim in mind of supporting “scalable, real-time targeting”, said Gerber. The firm is looking at using its free audience research tools to provide a basis for paid-for addressable advertising services.

Gerber added: “I’d ask you to think about why ComScore is so focused on us – a two-year-old start-up – and our methodology. What are they so worried about?”

Back in 2007, ComScore’s methods came in for criticism from Randall Rothenberg, president of the US IAB, who said the use of “outdated” panel methodology by both ComScore and its main rival NetRatings (now part of Nielsen Online) could lead to audiences being undercounted.

Later that year, Nielsen Online’s Asia Pacific boss Allan Dib was quoted as saying that the Australian IAB’s focus on accrediting panel measurement techniques was a ‘step backwards’ because of the difficulties of measuring smaller sites – although the company later insisted Dib’s remarks were taken out of context.

Author: Robert Bain

Related links:

Quantcast bags big-name support from MTV