Consent Management Platform

cmp · consent management platform · cookie consent · consent banner · cookie banner · consent management

Definition

A CMP has three jobs: (1) show the user information about cookie categories and request consent; (2) store the proof of consent as an audit trail; (3) block or enable analytics and marketing scripts according to the user's choice.

How a CMP works

The user opens the site
      v
The CMP shows the cookie banner
      v
The user chooses: accept all / essential only / customise
      v
The CMP stores the consent (cookie + server record)
      v
Based on that consent it enables or blocks the tracking scripts

Cookie categories by consent requirement

Category	Examples	Consent
Strictly necessary	Cart, authentication	Not required
Functional	Saved language, saved filters	Required or not, depending on jurisdiction
Analytics	Google Analytics and other analytics platforms	Required
Marketing	Retargeting, advertising pixels	Required

What a CMP does to personalization data

With a high refusal rate — 20–40% is typical in the EU:
– ML models train on incomplete data
– Affinity profiles are built only for users who consented
– Analytics understates the real numbers

The answer: server-side tracking, a first-party data strategy, and Consent Mode for aggregated modelling.

Frequently asked questions

Why does an e-commerce site need a CMP?

GDPR requires explicit consent for non-essential cookies, meaning marketing and analytics. Without a CMP and a record of consents a site is in breach, which in the EU can mean fines of up to 4% of annual turnover. CCPA in California and Russia's personal data law impose comparable consent duties in their own jurisdictions.

How does a CMP affect personalization and analytics?

Users who have not consented to analytics and marketing are invisible to tracking tools. On average 20–40% of users decline non-essential cookies, which leaves gaps in the data. That affects the accuracy of analytics, of segmentation and of personalization ML models.

What is cookie-less tracking?

Alternative approaches to tracking without third-party cookies: server-side tracking (data collected on the server with no cookie), first-party cookies (set by the site itself), fingerprinting (not recommended, it violates privacy expectations) and Google's Consent Mode, which passes aggregated data with no personal identification.

Consent Management Platform

How a CMP works

Cookie categories by consent requirement

What a CMP does to personalization data

Frequently asked questions

Related terms

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