Cookie-less ② Actions to Take Right Now


This post is a sequel to “Cookie-less ① From the Basics to Actions to Take” explaining what we can and should do in a movement toward a Cookie-less world.(*This post is based on information as of October 4, 2021.)

Physical measures against Cookie-less environments

Summary of measures for each platform
Measures proposed by each platform and their effects
  1. Google
    1. Google click ID
      A parameter that is passed to the URL when an ad is clicked. Records the site inflow from domains as First-party. Requires Google auto-tagging.
    2. Extended conversion
      Sends the hashed First-party customer data (e.g., email address) to Google and checks against the Google account the user was logged in.
    3. Server-side tag
      Transfers the tag processing done when a user visits a website to the new GCP server-side container.

  2. Yahoo!
    1. Click ID
      A parameter that is uniquely issued to the URL for each ad when the ad is clicked. Records the site inflow from domains as First-party.
    2. Local storage
      Data storage area/function of the web browser. It is in a separate area from cookies.

  3. Facebook
    1. Advanced Matching
      Sends the hashed First-party customer data (e.g., email address) automatically retrieved via tags to Facebook.
    2. Conversion API
      Sends hashed data such as customer data and user actions on the Web from the advertiser’s server to Facebook’s.

  4. Line
    1. Advanced Matching
      Sends the hashed First-party customer data (e.g., email address) automatically retrieved via tags LINE.

  5. Twitter
    1. Click ID
      An ID that is uniquely issued to the URL for each ad when an ad is clicked. When the Twitter website tag is activated, the tag reads this ID and sends it to Twitter, linking the visit with an ad click.

  6. Criteo
    Although not shown in Figure 1, Criteo is promoting user acquisition measures by utilizing the following targeting methods:
    1. User-level targeting
      1st Party Media Network development. 1st Party Media Network is a system that Criteo has been developing, combining commerce data and AI. It associates IDs and reaches users cross-domain. Based on first-party IDs of advertisers and publishers, the ID is combined with additional ID signals such as hashed emails and third-party IDs (e.g., LiveRamp’s RampID) and identifies users across domains.
    2. Interest group level targeting
      Cohort and participation in the Privacy Sandbox.
    3. Context targeting
      We are developing and testing a new product that displays ads related to the content of a web page being viewed.
– Effectiveness of the measures

In response to the restrictions on Third-party Cookies, every platform promotes measures with two main objectives.

  1. Cookies, including retargeting
    Retargeting ads are ads delivered to users who have visited your website before. But with the restrictions on Third-party Cookies, the distributions of retargeting ads are shrinking. It is recommended to maintain the results of retargeting ads by supplementing the visiting user measurement.

  2. Complementation of conversion measurement
    Complementing retargeting is not enough to cover the impact of the restrictions. This is because Third-party Cookies are also used to measure the effectiveness of ads, including retargeting ads. Therefore, there is a high possibility of omitting conversions obtained through ads. It is essential to take the recommended measures for each platform to maintain ad performance.

Impacts that cannot be avoided

Unfortunately, it is said that it is impossible to maintain the same ad performance as before even if all the retargeting and conversion measures explained above are implemented.

This is because there is still the problem of measurement period restriction. In addition, the revised Personal Information Protection Law, which will be enforced next year, will decrease the number of measurement targets because it will restrict the measurement target users to only those who have agreed to provide Cookies and IDFAs to third parties.

Preparation to adapt to the Cookie-less world

Up to here, I have summarized the measures and impact of each medium. And based on them, I recommend that marketers take action with the following in mind:

  1. Assess effectiveness based on the current advertising results
    Due to shrinking remarketing volumes and conversion measurement omissions, it will become increasingly difficult to compare results with the past ads. If you feel that the CPA of your ads has been rising recently, you may be able to feel the impact of the Cookie-less world on ads by checking if the unit cost of remarketing ads is increasing or if conversions are decreasing.

  2. Consider implementing measures
    With advertisers and agencies working together, implement Cookie-less measures. There are many complex system-related tasks to complete, and some may require about 2~3 months from organizing requirements up to the implementation.

  3. Consider distribution methods not depending on acquisition through retargeting
    Many advertisers may use non-retargeted ads to supplement the volume of retargeted users. But with retargeting no longer available, it is crucial to expand the distribution of non-retargeted ads as soon as possible.

  4. Review KPIs
    So far, I have explained the measures and their impact on Cookie-less ad distribution. However, the measurement will not be perfect even if all measures are implemented. Since it will no longer be possible to compare advertising cost efficiency results against those in the past, advertisers should again consider what they will use as KPIs. For example, you may look at the correlation between Cookie-independent indicators (such as sales data managed by the company) and advertising measures.


The restrictions on Third-party Cookies have progressed to the point where both advertisers and agencies must consider reviewing CPA targets and evaluate ad performances using metrics other than conversions. In the next post, we will discuss an example of a KPI and Irep’s recommended designs.

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