Comscore: What They Do and How Their Rankings Work

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What is Comscore?

Comscore is a media measurement and analytics company. As audiences have become increasingly fractured across various platforms and devices, Comscore acts as a third party that accurately measures audience engagement across TV, online sources, and beyond. This enables enterprises to have a better idea of which demographics are consuming media, which in turn allows them to better connect with — and advertise to — their target market.

Third-party media measurement is a useful tool. It provides greater transparency for both media and marketing, meaning brands can make advertising decisions with greater accuracy and with a relevant audience in mind. A simple example is a clothing line that is targeted towards younger adults. The advertiser can consult with Comscore rankings and choose to place ads between shows or websites with a demographic composition in line with their customer base.

What are Comscore Rankings?

Comscore’s ranking system is an aggregated list of their audience measurement services across platforms like TV, mobile, and online. It is further broken down into five measurements: total unique visitors or viewers, reach, composition index UV, total hours per month, and average time spent per month. 

Total Unique Visitors / Viewers

This number represents individual visitors to a site or service. As media engagement has become more fragmented over recent years, this figure has become more relevant. It captures the number of unique viewers over multiple platforms or sessions.


In Comscore rankings, reach is measured as a percentage of the population that views a particular platform. For example, Google sites might feature a high reach with around 98% or more of the total audience represented.

Composition Index Unique Visitors

The composition index is a measurement of a target audience’s concentration within a particular website or ad network. It divides the composition of a target market by the composition of the entire viewers. For example, if a YouTube channel gets 100,000 unique viewers per month, and 25,000 of them fall within a target demographic, the channel has a composition index of 25%.

Total Hours/Month

This measures the total hours per month that each unique demographic spends on a website or ad network. 

Average Time Spent/Month

This tracks the average amount of time (in hours and minutes) that a consumer interacts with a website or ad network in each sitting. 

Why Should Publishers Care About Comscore?

Comscore is important to publishers because most ad networks in the top 50 digital properties partner with them. However, this means the ad networks require publishers to sign a Traffic Assignment Letter. As a result, this directs the publisher’s traffic through the ad network, allowing the ad networks to comprise multiple large streams, which it leverages to attract larger advertisement deals.

This has advantages and disadvantages for publishers. In theory, it allows publishers to have access to potentially larger advertisement budgets, but how much of those revenue streams reach the publishers is a point of contention. By signing a contract with Comscore, publishers can’t diversify revenue streams and, in most cases, they are giving a larger share of advertising revenue to the ad network.

Publishers stand to benefit from a more transparent view of the revenue streams to protect their audience’s value. By signing an exclusivity contract for their traffic, publishers lose control of their audience metrics. The Ad Ops space is known for its inefficiency, with a Technology Business Research (TBR) study suggesting that publishers or media see only around 40% of digital advertising budgets. That figure highlights the benefits of taking back some control for publishers, with processes like split testing and gathering reliable analytics helping take advantage of the impressions and visits they generate.

The Future of Comscore

Comscore itself faces an uncertain future. With stock prices plummeting over the last five years, the measurement company has faced increasing criticism from publishers. Indeed, there have been significant questions about Comscore’s tracking over the last decade, including a controversy in 2010 involving the Comscore pixel. 

In short, with Quantcast and Google offering free traffic pixels to count web traffic, Comscore was found to be undercounting their audience by using a panel-only approach. Comscore responded by introducing a hybrid model for its paying users, effectively forcing users to pay to have traffic counted accurately. As of 2020, the minimum fee to use Comscore was $9,600 per year.

Another point of discussion is that Comscore’s measurements mostly benefit the digital properties that appear in its top 50 list and provide negligible value for publishers.

While the top 50 digital properties amass their publishers’ traffic to compete for large advertising budgets, it’s unclear whether Comscore’s measurements help publishers in this more contemporary digital landscape. While dangling a share of these large budgets in front of publishers seems appealing, many publishers realize that they — not Comscore — are the party generating and cultivating these lucrative audiences.

Considering this, many publishers are left asking whether or not they need a large ad network to act as an intermediary between them and advertisers. As publishers put in the work to generate the traffic, it’s unclear who needs whom in this relationship.

What are the Benefits of Website Traffic as a Publisher?

For publishers, website traffic is significant for several reasons. Depending on the specific publishers’ model, website traffic can generate revenue streams from advertisements or sales. More considerable website traffic also contributes to more significant sign-ups, subscriptions, engagement, sharing, growth, and, of course, a higher ranking in various search engine’s organic results pages.

By gaining control of the relevant metrics that make up their website traffic, publishers can get actionable insights that can drive greater growth and performance by understanding what their audience likes and responds to. Keeping audiences engaged and returning to their sites means that publishers can maximize the ad revenues associated with their hard-won audience. 

Considering these upsides, many publishers have reservations about signing Traffic Assignment Letters with ad networks that use Comscore. By taking back control of their web traffic and forging more direct partnerships and sponsorship deals with advertisers, many publishers have considerably increased their ad revenues.


While Comscore rankings were seen as the gold standard a decade ago, even then, many advertisers were skeptical about how those metrics translated into an effective marketing campaign. Superior analytic tools have turned digital marketing into a far more precise discipline. The internet has broken down a wall between publishers and their audience, and digital advertisers know and understand this. The feeling among many in the industry is that ad networks have become largely unnecessary for connecting brands with their desired demographics.

Comscore’s audience measurement metrics are still useful, but the digital advertising landscape has become a more sophisticated space through better ad tech and analytic tools. 

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