The accreditation does not cover traffic estimates for “non-Quantified sites” – those not using Quantcast’s tags – nor does it include Quantcast’s estimates of site demographics.

However, the development is notable for being the first time that a syndicated online traffic measurement service has received the seal of approval from the MRC, the media research auditor, certifying that it adheres to industry-agreed standards for online measurement.

Quantcast’s rivals Nielsen Online and ComScore committed to getting their web audience research services MRC-audited in May 2007, but for them the accreditation process is ongoing. Quantcast, by contrast, engaged the MRC in June 2008 – a year later.

Randall Rothenberg, president and CEO of the Internet Advertising Bureau, said Quantcast’s accreditation was a “milestone”, a “critical phase in meeting marketplace demand for full measurement service accreditation”. Rothenberg led demands for Nielsen and ComScore and to submit to MRC audits when he took the helm of the IAB in January 2007.

Meanwhile, MRC executive director George Ivie said: “We look forward to continuing our work with Quantcast to bring additional elements of its product line into the audit and accreditation process.”

Quantcast is a venture-backed business – funded to the tune of $52m – and is lead by CEO Konrad Feldman (pictured).