Chrome Data Analytics & Media (Chrome DM) has highlighted the growing importance of deduplication in measuring audiences across television, Connected TV (CTV), OTT platforms, YouTube, mobile devices and other digital platforms.

The company said advertisers today need to know not only how many impressions a campaign generated, but also how many unique people it actually reached. As audiences move across multiple screens and platforms, simply adding the reach reported by different platforms can count the same person more than once.

According to Chrome DM, ‘unduplicated reach’ is the final number of unique people reached, while ‘deduplication’ is the process of identifying and accounting for audience overlap across different platforms. The company said this shift has become important as media consumption becomes more fragmented.

Chrome DM’s COTT measurement ecosystem combines panel-backed measurement with passive digital consumption tracking. It is designed to provide a single view of audience consumption across CTV, mobile devices, OTT platforms and other digital environments. This can help advertisers identify audience overlap and understand how many genuinely new consumers each platform contributes.

The company said deduplication can help advertisers improve reach measurement, frequency management and cross-screen planning. Instead of looking at frequency separately on YouTube, OTT or television, planners can understand a consumer’s cumulative exposure across different screens and platforms.

Chrome DM also highlighted the importance of incremental reach. If two platforms have a high level of audience overlap, spending more across both may mainly increase frequency rather than reach new consumers. A platform with lower overlap could help advertisers reach audiences that were not reached through the existing media mix.

Deduplication can also provide a clearer view of effective frequency. For example, a consumer who sees an advertisement twice on television, three times on YouTube and four times on an OTT platform could have nine total exposures. Looking at each platform separately may not show this combined exposure.

The company said COTT can also help understand the relationship between linear television and CTV. Consumers may use the same television screen for linear channels, OTT applications and YouTube, while also moving between television and personal mobile devices. Measuring these overlaps can provide a more complete view of audience behaviour.

Chrome DM said deduplication can be used throughout the campaign cycle. Before a campaign, historical audience overlap can help identify suitable platform combinations. During a campaign, planners can monitor the growth of deduplicated reach and identify when platforms begin reaching the same audiences repeatedly. After the campaign, metrics such as Cost per Deduplicated Reach (CPDR) can be used along with traditional measures such as CPM.

Pankaj Krishna, Founder and CEO of Chrome Data Analytics & Media, said the industry needs to move beyond measuring impressions and platform-level reach and focus on understanding how much of an audience is actually unique. He said understanding audience overlap is important for measuring reach, frequency and media efficiency.

Chrome DM said the shift from ‘unduplicated reach’ to ‘deduplication’ reflects the changing media landscape, where audiences move across multiple platforms and screens. The company said cross-screen measurement can help advertisers, broadcasters and agencies understand who was reached, how often they were exposed and what each additional platform contributed.