VP of Digital Acquisition at American Express on measuring brand

How to measure brand work? Explained by VP of Digital Acquisition.

Last month, we sat down with Siya Liu, a teacher on our Mini-MBA course and VP of Digital Acquisition at American Express, for an honest, practical fireside chat about what “success” really means beyond sales for brands, how to guide agencies with the right KPIs, and how to make the research case when speed is everything.

Below are the highlights, in Q&A form.

Q: Siya, when doing brand projects with external creative agencies, which KPIs matter most for you — and why?

Siya: 

I use a clear set of KPIs split across lagging and leading metrics.

Lagging metrics focus on incremental accounts and revenue. Impressions don’t matter on their own — conversion does. You can build a large community, but if it doesn’t drive meaningful incremental accounts, it isn’t delivering value.

We also look at revenue quality. It’s not just how many customers you bring in, but whether they generate revenue and stay with us. Retention and long-term value are critical.

Leading metrics help us understand whether we’re on the right track early on. This is where research plays a key role, especially when the problem isn’t clearly defined. Rather than spending heavily and reviewing results after the fact, short- to mid-term research helps us course-correct early as channels and customer behaviours evolve.

Q: How do you evaluate brand performance long-term?

Siya:

External sentiment is critical. Alongside conversion metrics, track brand metrics and how they translate into business outcomes.

At American Express, we run regular brand research to measure perception across key dimensions like trust and security, benchmarked against competitors. We also track awareness. Sentiment shows how people feel about the brand; awareness shows whether it’s top of mind. This includes both unprompted and prompted awareness, with significant variation across markets that helps guide investment.

Awareness alone doesn’t drive revenue, so we measure intent, such as likelihood to apply, to understand how brand activity converts into action.

Over time, strong brand investment should translate into increased traffic, stronger intent signals, and ultimately growth in accounts and revenue.

Q: How to advocate for brand research budgets?

Siya:

First, research doesn’t have to be expensive. A solid quantitative study can cost around $10,000.

The key is framing. Position it as a tiny percentage of the overall marketing budget, sometimes as little as 0.2%, that dramatically increases confidence in decision-making.

Most importantly, tie the research to a specific business question. If it helps you make a clearer choice that impacts the bottom line, it becomes much easier to justify.

Siya is teaching more about measuring brand work at our Mini-MBA course for Designers and Creatives.

Q: Is it worth doing A/B testing for marketing campaigns or brand overhauls before going live?

Siya:

Absolutely, especially when you’re doing something fundamentally different. Qualitative research with just 6–10 people can quickly validate assumptions and surface reactions you hadn’t considered. Quantitative research then helps you measure things like intent to purchase or shifts in brand perception at scale.

Testing isn’t about slowing things down; it’s about avoiding very expensive mistakes.

Q: How to approach A/B testing in a company that prioritises speed and “just trying” over research?

Siya:

Most teams don't think they need testing because they assume performance is fine. Start with the data they already have. If you're running campaigns across multiple markets and one is performing three times better than another, ask: why? And wouldn't you want to replicate that success elsewhere? Framed that way, testing becomes a tool to scale what's working.

Benchmark against industry standards to show the revenue gap. Compare your conversion rates and cost per acquisition to industry benchmarks. If "great" performance means 3–4x more revenue, investing a small budget percentage to close that gap becomes rational.

Then get leadership aligned on just three metrics. Start small: pick one or two channels with easy testing tools, like Meta split testing, and frame it as scaling success, not adding work. When the opportunity is clear and tangible, testing becomes an obvious investment.

The takeaway:
Strong brands aren’t built on gut feeling alone. They’re built by combining creativity with the right metrics, smart research, and just enough testing to move faster with confidence.

💛 Learn more about the business side of brands from Siya Liu in our Mini-MBA for Designers and Creatives.