Privacy Centric Measurement (PCM) is Google’s solution to the recent flurry of data privacy changes seen throughout the technology and digital marketing industries.

PCM seeks to ensure that the data collected via Google Analytics is still reliable and accurate for data-driven marketers. PCM is a portfolio of measurement solutions designed to mitigate the challenges from privacy-related changes in the digital ecosystem.

Recent changes to user privacy

Rising user expectations on privacy are directly impacting the ability to accurately collect and measure data. These expectations have caused changes to platforms as well as privacy regulations.

Changes to platforms

Browsers, like Firefox, are already restricting the collecting of third-party cookies. We’re also starting to see companies, such as Apple, introduce operating system restrictions on the use of device identifiers to give users full control over their data and how advertisers use their information.

Changes to regulations

There has been an increase in restrictions on the use of personal data and additional requirements around user consent. The collection, use, and sharing of personal information to third parties with notice or consent have become a great concern to users across the world.

This is reflected in the rapid creation of data protection and privacy legislation worldwide. As it stands, 66% of countries have legislation whilst 10% of countries have draft legislation in place. These numbers highlight the importance of data privacy and what it means to the general population.

Principles of privacy-centric measurement 

Google has chosen three governing principles to abide by in regards to PCM. They are Preserve, Inform, and Secure.

  • Preserve: Preserve and leverage existing measurement while meeting user’s and legislators’ privacy requirements. Collection methods will still rely on cookies in the near term. Google recommends that your tagging solution is robust and durable.
  • Inform: Inform and augment gaps in data through additional data sources enabling comprehensive modeling. Additional signals are needed to help inform modeling.
  • Secure: Secure your data through additional controls on data storage and invest in privacy-preserving technology. The Google products required to do this process are still in the early stages of development. Cookies and these future solutions will coexist.

Impact of privacy-related changes for digital marketers 

This influx of privacy-related changes is making it harder for digital marketers to measure conversions, resulting in fewer conversions attributed to digital media and advertising. Collection methods impacted by these privacy changes are:

  • Legacy conversion tags
  • Third-party cookie data collection
  • Legacy analytic tools without cookie-less measurement

This directly affects digital performance as conversions are the foundations driving performance. Conversions feed into measurement solutions, such as attribution and incrementality, and the insights generated from these solutions feed into automation and optimisation which work together to maximise revenue.

If conversions can no longer be measured, measurement solutions wouldn’t work properly, meaning Google’s automation and optimisation solutions wouldn’t work properly which would result in reduced revenue.

Why act now? 

88% of browsers in APAC will restrict third party cookies in 2022

In 2015, there were no browsers restricting third-party cookies. If your measurement structure utilised third-party cookies, you could essentially measure everything.

As of today, in 2021, 16% of browsers (mainly Firefox, Safari, and Edge) in APAC restrict the collection of third-party cookies.

In 2022, this number will at least jump to 88% when Google Chrome begins to restrict third-party cookies. If other browsers in APAC choose to do the same then this number will be even higher.

If your current measurement infrastructure only relies on third-party cookies, next year when Chrome restricts third-party cookies, you won’t be able to measure conversions on almost all browsers in APAC.

12% of mobile phones in APAC already use iOS14

With iOS 14, Apple has started asking user consent to use device identifiers for advertising and measurement purposes. This has already directly affected conversion measurement. It has become even more difficult to attribute conversions from not only Safari at a browser level but also Apple devices.

Google’s PCM solutions 

Google plans to mitigate the risk of not collecting accurate and reliable data with several PCM solutions. Google has designed a portfolio of solutions designed to help advertisers build a robust conversion measurement foundation.

There are currently six solutions (Those marked high will require a technical resource to help implement the solution, those marked low will not):

1. Global Sitewide Tag

The global site tag (gtag.js) is a JavaScript tagging framework and API that allows you to send event data to Google Ads, Campaign Manager, Display & Video 360, Search Ads 360, and Google Analytics.

Instead of having to manage multiple tags for different products, you can use gtag.js and more easily benefit from the latest measurement features and integrations as they become available.

Google’s durable tagging solution relies on first-party cookies for conversion measurement. It is required for all other privacy-centric measurement and analytics products (Enhanced Conversions and Server-Side Tagging). (High)

2. Conversion Modeling

Conversion modeling refers to the use of machine learning to quantify the impact of marketing efforts when a subset of conversions can’t be observed.

Google’s machine learning algorithm enables you to fill gaps when conversions cannot be directly linked to ad interactions leading to more accurate reporting and optimisation. (Low)

3. Enhanced Conversion

Google’s Enhanced Conversions is a feature that can improve the accuracy of conversion measurement. It supplements existing conversion tags by sending hashed first-party conversion data from your website in a way that safeguards privacy.

It is a newer solution that aimed to collect data and recover conversions that are not observable by the site-wide tag, such as cross-device or impression-based conversions. (High)

4. Consent Mode

Consent mode allows you to adjust how your Google tags behave based on the consent status of your users. You can indicate whether consent has been granted for Analytics and Ads cookies.

Google’s tags will dynamically adapt, only utilising measurement tools for the specified purposes when consent has been given by the user. (High)

5. Server-Side Tagging through Google Tag Manager

Server-side tagging allows Tag Manager users to move measurement tag instrumentation out of their website or app and into server-side processing via Google Cloud.

Server-side tagging offers a few advantages over client-side tags:

  • Improved performance: Fewer measurement tags in a website or app means less code to run client-side.
  • Better security: Visitor data is better protected by collecting and distributing data in a customer-managed server-side environment. Data is sent to a Google Cloud instance where it is then processed and routed by other tags.

Server-Side tagging enables better site performance and security (by moving most of the site tags to the server) and improves measurement durability with server-only cookies. (High)

6. Conversion Measurement APIs

This API measures ad conversions (e.g. purchases) and attributes them to clicked ads without using cross-site persistent identifiers like third-party cookies.

This API will create an exchange of aggregate and privacy-safe data between the advertiser and the browser. This solution is still being prototyped and will not be ready for public use until 2022/2023. (Low)

What can be done right now?

The Global Sitewide Tag is required for new privacy-centric measurement analytic solutions. The Sitewide Tag allows measuring conversions with cookies set on a domain (first-party cookies). It can be set up via Google Site Tag (gtag.js) or Google Tag Manager. Gtag.js needs to be an implemented page of your website.

It is essential for the implementation of Google’s next-generation analytics tool, Google Analytics 4. The Sitewide Tag is also crucial for other solutions such as Enhanced Conversions, Consent Mode, Server-Side Tagging, and or Privacy Sandbox.

Another benefit of Global Sitewide Tag is the ability to recover click and call conversions in browsers restricting third-party cookies by storing Click Ad IDs as a first-party cookie instead.

To futureproof your measurement infrastructure, the best place to start is to implement the Global Sitewide Tag.