The crux of the deal between the web analytics and web measurement firms is the ability for customers of both companies to use Omniture tags to collect and share visitor behaviour data with ComScore’s Media Metrix 360 system.

So while ComScore gains access to clickstream data for websites, Omniture’s web analytics data can be fleshed out through the addition of demographic data collected through ComScore’s panel of web users.

Publisher Conde Nast’s SVP of research Scott McDonald described the tie-up as “the most significant effort to date” to harmonise the two different ways of measuring website audiences.

“Both census-level web analytics and person-based audience measurement services are essential to evaluating digital media performance,” added Larry Gelfand, SVP of digital sales and business development for the National Hockey League. “To finally see these two measurement technologies brought into alignment is an extraordinarily positive step for those involved in the digital medium.”

ComScore’s launch of Media Metrix 360 this summer marked a first attempt by the company to iron out discrepancies between server-side and panel-based web audience data by integrating both sources of data in a hybrid measurement system.

To be measured by Media Metrix 360, site owners had to mark up their sites using ComScore’s own tags. Effectively the deal with Omniture bypasses that process, allowing Omniture customers to report into Media Metrix 360 using their existing web analytics tags.

ComScore’s deal with Omniture is non-exclusive, meaning the potential is there for ComScore to develop similar arrangements with other providers of web analytics software and services.

Omniture recently agreed a $1.8bn deal to be acquired by design software firm Adobe.