From clicks to clarity: Media Mix Modelling Q&A with dentsu

How is the way your clients measure marketing performance evolving beyond last-click attribution?

“At dentsu, we approach the affiliate channel by focusing on the value publishers drive across the entire customer journey rather than relying solely on last‑click attribution. We utilise path‑to‑conversion reporting within affiliate networks to understand which partners have been involved throughout the purchase journey, not just those delivering the final click, whilst recognising that this view is limited to affiliate contributions rather than the full marketing mix, we feel it is still useful.

“To ensure fair partner compensation, we recommend implementing dynamic commission rates aligned to client KPIs, such as paying higher rates for new customer acquisition than for existing customers, and offering higher commissions, tenancy, or CPC models for upper‑funnel partners, as a flat CPA model may undervalue their contribution. For content partners, we have tools available that identify AI citation inclusions which some clients see as a measure of success, helping us evaluate historically hard‑to‑measure exposures that typically generate low last‑click revenue.

“We are also supported by internal data teams who run campaign‑level testing to assess incremental impact, although these tests generally need to operate at scale – such as card‑linked campaigns, rather than small‑level changes like adjusting CPA for a single publisher. Finally, we can complement these approaches with marketing mix modelling (MMM) to inform how budgets should be allocated across marketing channels.”

Where does affiliate marketing currently sit within your wider marketing measurement framework?

“Affiliate marketing typically sits alongside other performance channels within the broader measurement framework and is most often assessed using last‑click metrics. Our clients generally measure affiliate performance in two main ways: through analytics platforms such as GA4, where contributions from all channels are considered, and through affiliate network reporting, where last‑click performance is usually more prominent and therefore appears stronger than in other dashboards.

“In addition, affiliate data can be fed into marketing mix modelling (MMM) to evaluate incremental impact, with the insights used to help inform and optimise future budget allocation.”

What data or insights would help you and your clients better understand affiliate’s true influence and incremental impact across the shopper journey?

“Incrementality is a term frequently referenced within the affiliate industry, but its meaning can vary significantly between businesses, so we would need clients to clearly define what incrementality looks like for them. We do request client data to support internal analysis of the long‑term value driven by affiliate‑acquired customers; however, this information is not commonly available.

“We recognise that certain publisher types tend to attract higher‑quality customers than others, and access to customer lifetime value data broken down by affiliate would enable more informed and effective budget allocation decisions.”

How are privacy changes, AI search, and zero-click behaviour affecting the ability to measure marketing performance?

“Over the past few years, there have been instances where we’ve seen orders/revenue volumes drop off which correlate to privacy changes, but we have put best‑practice measures in place to minimise the impact as much as possible. We’ve recommended and implemented server‑to‑server (S2S) affiliate tracking as a priority whilst we have strongly recommended the use of “strictly essential” cookies for brands running cashback, loyalty, and reward programmes.

“While we also have access to a tool that highlights when affiliate content is surfaced within LLM results for specific search queries (helping to demonstrate the incremental value of content exposure), we currently struggle to measure the downstream impact of zero click/AI search results including traffic, conversions or revenue.”

What would make affiliate marketing more credible in senior-level marketing budget discussions?

“A shared understanding is needed that affiliate marketing functions as a full‑funnel channel, rather than being viewed purely as a lower‑funnel tactic that captures or diverts conversions. Affiliates are also uniquely positioned to reach customer segments that other channels often struggle to access, including students, emergency service workers, influencers at scale, and closed or gated user groups.

“As A/B testing within affiliate marketing is relatively rare, robust case studies from affiliate teams are particularly valuable to demonstrate incremental impact from tactics such as spend‑and‑save cashback or voucher offers, new‑customer commission rates, category or product‑specific incentives, and promotional messaging during key trading periods.

“This should be complemented by follow‑up analysis from internal client teams assessing the lifetime value and repeat‑purchase behaviour of affiliate‑acquired customers, alongside clear case studies from a wide range of partner types explaining how and why they are able to drive incremental performance against core KPIs.”