GAC Case Study: How Synthetic Personas Guided Creator Selection and Content Territories
Galaxies built five synthetic personas from research with real GAC Brazil consumers. They helped the automaker evaluate creators, narrow down content territories and test narratives before the campaign went to market.
In brief: GAC launched its brand in Brazil in June 2025 and wanted to turn influencer marketing into a strategic capability, not just a reach tool. Galaxies created five synthetic personas from research with real GAC consumers. The personas evaluated creators for product fit, credibility and conversion potential, and helped guide territories and narratives. According to GAC, average engagement rose from 1.26% in 2025 to 5% in 2026, while organic unique views from May to July grew from 4.6 million to more than 30 million, as a result of the overall strategy. Marketing Decision Intelligence is what we call the work Galaxies does: helping marketing leaders make decisions about creatives, claims, audiences and messaging before committing their budgets, using synthetic personas built from real research and human review. |
|---|
This is the account of a project with GAC Brazil, an automaker that entered the country in 2025, in partnership with agencies GreenZ and Suba. The partnership was reported by Propmark. The results below were released by GAC itself and refer to its influencer marketing strategy as a whole. Here, we explain the role of synthetic personas and the limits of what these results tell us.
What was GAC’s challenge with influencers?
GAC’s 2025 campaigns generated reach, but audience connection and the quality of interactions fell short of what the brand wanted. The average engagement rate that year was 1.26%.
Luis Fernando Guidorzi, Communications and Marketing Director at GAC Brazil, summarized the starting point in the case study video recorded with Galaxies:
“In 2025, we were still building our influencer marketing operation in Brazil. The challenge for 2026 was to understand how to turn influencer marketing into a more strategic capability for the brand, rather than just a tool for reach.”
For 2026, GAC defined five brand territories, including technology, lifestyle and economy, and structured a dedicated Creator Economy operation with a nationally recognized ambassador and quarterly squads of creators and UGC creators. What was missing was a method for discovering which creators truly resonated with each audience segment, one that could be repeated every quarter and tailored to the brand.
How were the synthetic personas built?
GAC’s synthetic personas were built from research with real consumers of the brand. The process groups respondents with similar answers, and each group becomes a persona. There were five in GAC’s project. The personas’ responses are simulated and grounded in that research: they help compare alternatives and review decisions before investing, not predict a campaign’s results.
In Nexus, this foundation is available for the team to explore questions and compare options before committing its budget.
How did GAC use the personas to select creators?
The five personas evaluated the influencers considered by GAC, both those from 2025 and those in the 2026 strategy, on three criteria scored from 0 to 10: product fit, credibility and ability to convert. The goal was not just to see who had the best performance indicators, but to understand which creators had the greatest ability to connect with each consumer segment within the brand’s communication context.
This was a retrospective validation. GAC submitted the influencers to the personas to check whether their assessment aligned with decisions the brand had already made.
Daniel Victorino, Co-founder and CEO of Galaxies, explained the exercise to Propmark:
“Galaxies needed to give GAC a repeatable method, not a one-off assessment. We built five synthetic personas from real research with the brand’s audience and proposed a retrospective validation exercise: we submitted the 2025 and 2026 creator lineups without access to campaign metrics, and the pattern emerged in minutes.”
According to Daniel, the fit score of the selected influencers rose from 7.5 to 8.0 between the two periods. These are simulated assessments, not observed conversion rates.
According to GAC, what had previously been a hypothesis to validate was confirmed by the study. The final data from the first quarter of work was not a surprise; it confirmed that the team was on the right track.
What decisions did the personas guide beyond creator selection?
The project went beyond choosing influencers. The study identified lifestyle, technology and economy as the territories with the greatest potential to increase brand awareness, but all three are very broad. The work helped identify which part of each territory connects best with GAC. Travel, for example, is a broad territory; getaways are travel viewed through the brand’s lens.
The personas also indicated which narratives, content formats and communication territories tend to create greater relevance for each segment. Guidorzi describes the effect on marketing:
“The most interesting part is that the project was not limited to choosing influencers. The personas also indicated which narratives, content formats and communication territories tend to create greater relevance for each consumer segment. This means marketing stops looking only at performance metrics and starts using data intelligence to design the entire communication operation.”
Today, GAC uses the personas to compare formats, messages and territories before each campaign cycle. Before hiring influencers, GAC evaluates audience profile, product fit, content territory, credibility and conversion potential. After each activation, it analyzes the results to guide its next decisions.
What were GAC’s results?
The figures below were released by GAC Brazil and refer to its influencer marketing strategy as a whole.
Metric | 2025 | 2026 | Note |
|---|---|---|---|
Average engagement rate | 1.26% | 5% | Nearly fourfold growth |
Organic unique views, May to July | 4.6 million | More than 30 million | More than sixfold growth; four-person squads with the same headcount and profile, without paid reach |
Organic views in July | N/A | 11.46 million | Plus 35,100 organic interactions |
The simulated fit score rose from 7.5 to 8.0 in retrospective validation. It shows consistency between the personas’ assessment and GAC’s choices, and does not measure campaign performance.
What do these results not tell us?
Three caveats help us read this case study honestly. First, the growth in engagement and views is the result of GAC’s entire strategy: the ambassador, quarterly squads, management structure, partner agencies and data analysis. The personas contributed validation and decision guidance; they do not explain these figures on their own.
Second, the scores of 7.5 and 8.0 are simulated, came from a retrospective exercise and show consistency between the personas’ assessment and GAC’s decisions. They do not measure the actual performance of each campaign. Third, this exercise must be distinguished from use in future campaigns: personas can support hypothesis testing before new activations, but retrospective validation does not demonstrate that they selected the evaluated lineups in advance.
What can marketing leaders apply from this case study?
The reusable method does not depend on the automotive sector. It starts with real research with the brand’s audience, moves on to evaluating creator selection, territory and narrative options against personas built from that research, and ends with analysis of each activation’s results, which informs the next decision.
For anyone planning the next quarter of influencer marketing, the question is simple: have the creator choices in the brief been tested against any signals from the real audience, or will the campaign be the first time the hypothesis meets the consumer?
The lesson is to turn creator selection, territories and narratives into hypotheses that can be compared with signals from the brand’s audience. The team remains responsible for the decision and for interpreting real results.
In closing: decide before, measure afterward
GAC’s case shows a use of synthetic personas that goes beyond generating answers: giving a marketing team a foundation for decisions before a campaign and, afterward, learning from what happened. Research with real consumers remains the starting point, and measurement of real results remains the final judge. This is how we narrow what we call the Signal-to-Decision Gap, the interval between the consumer signal and the brand’s decision.
To understand how this approach can support your planning, explore Nexus. See also Galaxies’ use cases or request a demo with a real question from your team.
Frequently asked questions
What did Galaxies do in the GAC project?
It built five synthetic personas from research with real GAC consumers. They evaluated influencers for product fit, credibility and conversion potential and guided content territories, narratives and formats.
Do synthetic personas explain GAC’s increase in engagement?
Not on their own. According to GAC, average engagement rose from 1.26% in 2025 to 5% in 2026 through the overall strategy, which includes an ambassador, quarterly squads, specialized management and data analysis. The personas contributed validation and decision guidance.
How did the personas evaluate influencers?
With scores from 0 to 10 on three criteria: product fit, credibility and ability to convert. The evaluation was retrospective for the 2025 and 2026 influencers and compared the personas’ assessment with decisions GAC had already made.
Where does the data for GAC’s personas come from?
From research conducted with real GAC consumers. The personas were calibrated with data from the brand’s audience, not a generic panel.
Does persona simulation replace consumer research?
No. Real research is the foundation that feeds the personas, and measuring actual campaign results remains necessary. Personas support decisions before execution.
Sources cited
Propmark. GreenZ, Suba and Galaxies combine AI and influencer marketing in a strategy for GAC. Published October 26, 2026.
GAC Brazil and Galaxies. Case study video with Luis Fernando Guidorzi, Communications and Marketing Director at GAC Brazil.
Galaxies. Press: company coverage and announcements.