It is the first big client win for the new measurement system which aims to provide a means of gauging audience size and reach that is comparable to TV ratings.

Nielsen will provide Unilever with reach, frequency and gross rating point measures for campaigns featuring any of the 40 brands it has on the market in the US. A UK roll-out is expected later this year.

Unilever’s Jennifer Gardner, director for media investment and partnerships, said: “In our business, we look for the best marketing return on investment — and the best tools to gauge that. The Nielsen online campaign ratings platform is an exciting resource that brings a more rigorous standard to our online campaigns and consistency in measurement strategy across our portfolio of brands.”

Online campaign ratings are produced through a combination of traditional Nielsen TV and online panel data mixed with aggregated, anonymous demographic information from participating online data contributors.

The system works using pixel-tracking, so that when a particular display or video advertisement is shown in a browser this is reported to Nielsen and to other approved data contributors – including large web publishers. These contributors then provide aggregate-level reports containing reach and frequency information in anonymous age and gender buckets.

Nielsen says it will then use proprietary technology to combine these reports with data from its TV and online panels, resulting in a single report showing reach, frequency and GRPs for the advertisement. Meanwhile, a second process runs in parallel to match the IP address of the pixel to one of the 210 Nielsen Designated Market Areas (DMAs).