Your long-term strategy should be building relationships, not renting audiences

For over a decade, third-party data has fuelled digital advertising. By tracking consumers across websites and sharing that data between unrelated brands, marketers have been able to target ads based on online behaviour, often without ever knowing who the customer really is.

That model is unravelling.

Concerns over privacy and fair competition have triggered sweeping changes from major tech platforms. Apple and Mozilla have already blocked third-party cookies. Google, after years of planning to phase them out, has recently reversed its course. In July 2024, Google announced that it would no longer proceed with the deprecation of third-party cookies in Chrome. Instead, it will maintain the current approach and allow users to manage their cookie settings through existing privacy tools.

The core issue is that using external data means renting audiences rather than building relationships. It creates reliance on intermediaries whose policies can change at any moment. That fragility makes third-party data a shaky foundation for long-term strategy.

Instead, brands are shifting to first-party data, which is information collected directly from customers through purchases, website activity, loyalty programmes, and email engagement. It is not only more privacy-safe but also more accurate, more cost-effective, and more actionable. First-party data enables marketers to personalise outreach, understand buying cycles, and forecast demand with greater precision.

However, many companies struggle with fragmented and inconsistent data. Is AB Smith, the loyalty member, the same person as Angie Smith on the email list or Angela Smith from a third-party file? Disconnected records and duplicate identities degrade customer intelligence and undermine campaign performance.

Even brands that have invested heavily in first-party infrastructure often find themselves stuck. Inconsistent personally identifiable information (PII) makes it difficult to clean, unify, and activate data at scale. That fragmentation blocks a clear view of the customer journey and leaves valuable insights and return on investment out of reach.

Artificial intelligence (AI) is proving essential. AI can resolve mismatched data across systems and channels to create a unified customer profile. This shift not only improves accuracy, it also returns control to marketers by reducing reliance on opaque ad networks.

With a unified view of the customer, brands can orchestrate omnichannel marketing campaigns through SMS, loyalty offers, dynamic content, and in-store experiences. All of these are powered by trusted, privacy-compliant data. From a security standpoint, managing one consolidated source of truth also lowers the risk of breaches.

The impact on paid media is especially significant. AI-powered measurement tools now enable marketers to track the full effect of digital advertising across both online and offline conversions. This level of visibility allows for smarter budget allocation and daily optimisations to maximise return on advertising spend.

Third-party data is not vanishing overnight, but its dominance is clearly waning. Brands that invest in their own data foundations now will gain more than just compliance. They will earn resilience, agility, and the ability to build more meaningful, durable relationships with their customers.