The Future of Cookies & Your Marketing Strategy Blog Post

Navigating the Evolving Landscape: The Future of Cookies & Your Marketing Strategy

In Analytics, The Digital Marketing Blog by SeanLeave a Comment

In the ever-changing world of digital marketing, a significant shift is happening with the ongoing deprecation of third-party cookies. This is one of the biggest changes in marketing over the last 20 years and it aims to put an end to the pervasive tracking of users across the web for advertising purposes. 

As the industry prepares for these upcoming changes, the importance of first-party cookies and data sources becomes clear for marketers. Unlike third-party cookies, first-party cookies are not easily blocked by ad blockers and browser restrictions, offering a more robust foundation for data collection. While obtaining consent for data collection remains necessary, the reliability and future-proofing offered by first-party data is significant.

Yet, the specifics of a world without third-party cookies remain somewhat uncertain. Discussions about change are everywhere, but the practical details are unclear. The Privacy Sandbox initiatives by Google are still in development; it’s uncertain what changes they will bring to Chrome and Google Ads.

In this article, we delve into the details of browsers and platforms, figuring out which ones have embraced or resisted the depreciation of third-party cookies. We also explain the impact this deprecation will have on marketing and websites. 

Read on to learn how you can get ready for this upcoming change. There’s a lot to digest, so grab a coffee and a mince pie, and settle down for a while!


Cookie Definitions

Let’s first understand the differences between the two types of cookies before we discuss the upcoming changes. 

Third-party cookies: The cookie from a website you aren’t browsing at the time.

First-party cookies: The cookie from the website you are browsing at the time.


Third-party Cookie Deprecation Timeline

The depreciation of third-party cookies has been gradual over the last few years. The below timeline contains the key milestones since 2019, including information on the platforms that haven’t been forthcoming on how and when they’ll make this change.

  • 2019: Google announced it plans to phase out support for third-party cookies in Chrome by 2022
  • 2019 – 2020: Firefox and Safari blocked third-party cookies by default
  • 2021: Google introduced Privacy Sandbox, an initiative to develop privacy-friendly technologies that will replace third-party cookies
  • 2022: Google delayed its plan to phase out third-party cookies in Chrome until 2023, stating it required more time for testing and getting input from developers and marketers
  • 2023: Google intends to deprecate third-party cookies in Chrome in the second half of 2024; the deprecation will be gradual and begin in the first quarter of 2024

The above shows what some of the big tech providers like Google have done. In spite of this, Meta and Microsoft Ads haven’t followed in their footsteps.

Meta doesn’t appear to have said they’ll phase out third-party cookies. A few years ago, it released a first-party tracking pixel to enable tracking in browsers like Safari, where third-party cookies are blocked. The pixel allows you to continue measuring ad performance across browsers. So far, this seems to be the only indication that Meta is preparing for a time without these cookies.

Microsoft Ads uses third-party cookies and doesn’t appear to have said when they’ll phase these out. The Microsoft Audience Network allows you to use either its own first-party data (e.g. search data from Bing) or your own (e.g. your Customer Relationship Management (CRM)). As with Meta, this appears to be Microsoft’s only indication that it’s preparing for this cookie change.

Google Analytics hasn’t been referenced above because it uses first-party cookies. So you can be reassured that Google Analytics 4 (GA4) will continue to collect data throughout the above changes.


The Impact of Third-party Cookie Deprecation & What To Do about It

Our research shows there are still many unknowns, particularly regarding the changes in Chrome and Google Ads. Google Ads will undergo changes as part of the ongoing development of Google’s Privacy Sandbox. However, the specific details of these changes have not been revealed yet. 

From what we’ve been able to uncover so far, there are 7 areas of change to prepare for. In this section, we’ve summarised what these changes are likely to be and how you can prepare for them. You probably won’t be surprised to know that Paid Advertising and Analytics are the areas where you’ll see the biggest impact.

Ad Targeting

Audience Targeting will Rely on First-party Data

Advertisers should use first-party data sources, such as GA4, to create audiences that can be shared with advertising platforms. You can use features like Google Ads’ ‘customer match’ to upload contact information of customers from your clients’ CRMs. Google then matches the information to that of Google users, so you can serve ads to them. You can use ‘similar audiences’ to create groups of people who are like your ‘customer match’ audiences. These audiences are made up of people who are likely to respond well to your ads.

This will extend to remarketing, i.e. you’ll need to rely on first-party data sources like your clients’ CRMs to build remarketing audience lists. You won’t be able to track users around the web and serve them with ads based on first-party data. You should still be able to target people who have visited your website and then show them ads when they’re on a different website. Google is still working on how they’ll enable this without third-party cookies though.

Contextual Targeting will Replace Behaviour-based Targeting

For years, the typical way of reaching website users with ads is by targeting them based on how they behave on those websites. For example, a user visits a page on pink shoes, so you serve them with an ad for pink shoes. 

When third-party cookies are no longer used, we won’t be able to track users as they navigate between websites. As a result, we’ll need to depend on the contextual advertising methods below. This involves targeting people based on the content of websites. For example, if we’re selling pink shoes, we can decide to run ads for our shoes on websites that have content about shoes. Ad platforms like Google enable these methods with third-party cookies at present, but we suspect this will change. This is ultimately a move away from more precise targeting, but Google hasn’t provided details on how these changes will work or when they will happen.

Methods for Contextual Advertising:

  • Keyword Targeting: Serves ads based on the keywords present on the page where the ad appears
  • Topic Targeting: Serves ads based on the topic of the page where the ad appears
  • Placement Targeting: Serves ads based on the specific website or app where the ad appears

Machine-learning Solutions will Provide Ad Measurement

Without the ability to track users across websites, it becomes impossible to understand their interactions with websites or competitors’ ads. You’ll need to rely on alternative methods like conversion modelling, which estimates conversions based on the likelihood that a user with certain behavioural characteristics will have converted. Conversion modelling is now easier with the introduction of GA4. It uses machine learning to bridge the gaps in conversions when users haven’t consented to data collection. Therefore, it’s very likely that Google will release more machine-learning solutions to help measure your ads’ performance.

Smart Bidding Strategies will become The Norm

These strategies optimise bids in real-time by using various signals like the below to show users highly relevant ads. Analysing and optimising for so many signals isn’t something that can be achieved by one person doing this manually. 

  • Operating system
  • App
  • Browser
  • Language
  • Query
  • Ad creative
  • Time of day
  • Location
  • Search partner

Smart bidding however, uses machine learning to read the user’s search query and signals like the above that help indicate the user’s intent, allowing the best possible ad to be served to that user. This approach is both highly effective and designed to last because it doesn’t depend on third-party cookies or data sources.

Frequency Capping

Limiting the number of times an ad is shown to a user to prevent ad fatigue will become more challenging. This is because it currently depends on tracking individual users using third-party cookies. Users might see the same ads over and over again, which could make users tire of them and cause click-through rates to decrease.


Without the ability to track user behaviour, ad personalisation will be less accurate. Users can disable ad personalisation in the browsers and apps they use. As a result, the impact of deprecating third-party cookies may not be as significant. Customising ad copy or images based on user behaviour or search queries will become more challenging. Tailoring ads based on demographic information will also be harder if ad platforms no longer have access to this information.

Analytics Platforms & Tracking

Attribution & Performance Measurement

Attribution models will be affected due to the difficulty in connecting each user’s online touchpoint in their journey. This makes it more challenging to determine the effectiveness of each channel at generating conversions.

As third-party cookies are no longer available, machine learning models and predictive analytics will be used more to estimate missing conversions.

Encourage users to sign in to your website or app to collect data using first-party cookies. These cookies can be used to store each user’s session ID, which can be used to recognise the user across sessions. This will help increase the accuracy of user, session and conversion data.

Server-side Tracking

Move away from client-side/browser-based tracking by using server-side tracking, which doesn’t use cookies. Tracking blockers, such as browser-based ones for ads and Apple’s Intelligent Tracking Prevention (ITP) for cross-site tracking, are bypassed. This improves the reliability of data collection. The cost of purchasing a server and employing resources to maintain it must be considered though, and consent to data collection is still required.

Privacy-centric Platforms

Use platforms that don’t rely on third-party cookies. GA4 is an example of this because it uses first-party ones. There are also platforms that don’t use cookies at all, e.g. Plausible and Fathom. 

These types of platforms will help future-proof your data collection strategy because they don’t rely on third-party cookies. Instead, they can use machine learning to estimate online conversions when first-party cookies are limited. These limitations include:

  • Being unable to identify a user if they’ve signed in to a website via a different device or browser to the one that set the cookie
  • When a user has deleted the cookie

Consent Management

Securing consent from users to data collection will still remain non-negotiable for remaining compliant with privacy regulations. Keep using a Consent Management Platform (CMP) like Cookiebot to ask for consent and manage which tools can/can’t set first-party cookies. Continue to be open and honest with users about the data you collect and how it’s used. This will allow them to make informed decisions about giving their consent.

Chrome already has controls that let you enable/disable features, such as ad measurement and the collection of interest topics. These features are used by websites to display personalised ads. The controls are only likely to expand for users.

Website Functionality

Functionality could be affected if it relies on third-party cookies. For example:

  • Login authentication
  • Login to Social Media accounts
  • Embedded content from third-party sites, e.g. videos, maps and Social posts
  • Widgets from third-party sites, e.g. functionality for payments, calendars, bookings and reservations. Social sharing buttons that are provided via widgets could also be affected

Your developers will need to understand how your website uses third-party cookies, so they can find a different solution.

Audience Profiling

Detailed user profiling will be reduced if your profiles are built with third-party cookie data. It will be difficult for you to understand how users behave, and their views and preferences without access to extensive information about their behaviour across the web. Using more zero-party data sources, such as customer interviews and surveys, can provide you with an alternative way to profile your audience.

Greater Ad Budget Allocation to Big Players like Google

Google, Facebook and Amazon already dominate online advertising because of how well-used they are for finding and buying products/services. Advertisers may become more dependent on them due to their extensive first-party data. This will result in a greater portion of advertising budgets being allocated to them.

Return to Traditional Measurement Methods

In recent times, there’s been a resurgence of the more traditional measurement methods below:

  • Incrementality Testing: It identifies the causal impact of a marketing campaign through testing. The tests are similar to A/B ones that are used in conversion rate optimisation. Half of your audience sees the campaign and the other half doesn’t. The different result between the two segments is the incremental impact of the campaign
  • Media/marketing Mix Modelling: This identifies the effectiveness of marketing channels through multiple linear regression, which uncovers the relationship between marketing spend and conversions

Small and medium-sized businesses (SMEs) often aren’t able to easily access these methods. This is because they either lack the expertise to develop and manage the technology in-house, or they lack the budget to hire external agencies to conduct the testing. Interpreting the results still requires expertise within the organisation to assist clients and colleagues in understanding the testing and modelling conclusions. In the future, these will be affordable SaaS products with user-friendly interfaces that marketers and data analysts can easily use.

Potentially, Google Ads’ ‘conversion lift’ feature will allow businesses to start experimenting with incrementality tests. It’s not yet available for all accounts and you’re limited to running tests for ‘video action’ or discovery campaigns for now.



The impending deprecation of third-party cookies is a pivotal shift in digital marketing. Marketers should plan to transition towards using first-party cookies and data sources as a future-proof data collection method. Their immunity to ad blockers and browser restrictions means they’re invaluable assets in this way.

While discussions about a post-third-party cookie world continue, the practical details remain unclear. This is especially true for Chrome and Google Ads. Google’s Privacy Sandbox initiatives will offer answers, but we’re uncertain about when and how much information will be provided.


Contact Us

Ensure your marketing team and developers know about the themes discussed in this article and are getting ready for the upcoming changes. If you need advice on what more you can be doing, leave a message via the contact form below or call us on 01273 733 433.

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