The CX Growth Index (CXGX): A New Standard for Measuring and Prioritizing Customer Experience Investments in Banking

Rethinking Customer Experience Measurement in Banking

In today’s hyper-competitive banking landscape, customer experience (CX) is no longer a differentiator—it’s a necessity. As digital-first challengers and fintechs continue to raise the bar, established banks are under increasing pressure to deliver seamless, personalized, and memorable experiences across every channel. Yet, while most banks recognize the importance of CX, many struggle to measure its true impact on business growth and to prioritize investments that will move the needle.

Traditional metrics like Net Promoter Score (NPS) have long been the industry standard for gauging customer sentiment. However, NPS offers only a high-level snapshot, lacking the granularity and actionability needed to drive meaningful change. Banking leaders are asking: How can we link CX investments to tangible business outcomes? Where should we focus our resources to maximize growth and retention?

Enter the Customer Experience Growth Index (CXGX)—a proprietary framework developed by Publicis Sapient to provide banks with a rigorous, data-driven approach to measuring, benchmarking, and improving customer experience at the touchpoint level.

Introducing the CX Growth Index (CXGX)

The CXGX is designed to go beyond NPS by capturing the full spectrum of customer interactions and emotions across all channels. Built on the “Three E’s” framework—Experience, Expectation, and Emotion—the CXGX surveys customers after specific interactions, asking:

Did you get what you wanted?
Was the experience better or worse than you expected?
How did the experience make you feel? (with 18 possible emotional responses, from angry to uplifted)

Each response is linked to one of 11 key banking touchpoints, including call centers, desktop and mobile websites, mobile apps, live chat, email, social media, text, branch visits, and more. This approach provides a granular, channel-specific view of customer experience, allowing banks to pinpoint which interactions delight customers—and which drive them away.

Why Move Beyond NPS?

Banking CX leaders in the UK and beyond are increasingly vocal about the limitations of NPS:

“NPS isn’t a nuanced enough metric to properly measure experience.”
“We’re shifting away from NPS to tracking metrics that are proven to be leading indicators of great experiences.”

The CXGX addresses these gaps by:

Delivering actionable, touchpoint-level insights
Linking CX performance directly to business growth and retention
Enabling banks to benchmark against competitors and digital leaders

How CXGX Links Customer Experience to Business Growth

The power of the CXGX lies in its ability to correlate customer experience scores with future business outcomes. Analysis of UK retail banks using the CXGX framework reveals:

Banks with higher CXGX scores see greater net growth in customer numbers. For example, neobanks with top CXGX scores have gained tens of thousands of new customers, while lower-scoring incumbents have seen net losses.
CXGX scores are strongly correlated with future usage intention. Customers who report positive, memorable experiences are significantly more likely to use the bank’s services again and recommend them to others.

This predictive capability transforms CX from a “soft” metric into a leading indicator of growth, providing executives with the confidence to invest in the experiences that matter most.

The CXGX Methodology: Turning Data into Action

The CXGX framework enables banks to:

Map the Customer Journey: By linking survey responses to specific touchpoints, banks can visualize the entire customer journey and identify which channels drive the most positive (or negative) experiences.
Score Each Touchpoint: Each interaction receives a CXGX score, ranging from +100 (strongly positive) to -100 (strongly negative). Satisfactory but unremarkable experiences cluster around zero—the “Valley of Meh.”
Prioritize Investments: By combining CXGX scores with usage data, banks can see where to focus their efforts for maximum impact. For example:
- If a mobile app scores highly but has low adoption, driving more customers to use it can boost overall CXGX.
- If live chat outperforms call centers in both CX and cost, migrating more customer service interactions to chat can improve satisfaction and efficiency.

Example: UK Retail Bank Value Chain

A leading UK bank’s CXGX analysis revealed:

Mobile app: Highest CXGX score, but not all customers use it.
Desktop website: Lower score, but high usage.
Live chat: Outperforms call centers in CXGX and cost, but underutilized.

By encouraging even a small percentage of desktop or call center users to switch to the mobile app or live chat, the bank could significantly improve its overall CXGX—and, by extension, its growth trajectory.

Practical Guidance: Using CXGX to Drive CX Investment Decisions

The CXGX framework empowers banks to make data-driven decisions about where to invest in customer experience. Here’s how:

1. Benchmark and Diagnose

Use CXGX to benchmark your bank’s performance against competitors and digital leaders.
Identify which touchpoints are underperforming and which are exceeding expectations.

2. Prioritize High-Impact Channels

Focus investment on channels with the highest CXGX scores and growth potential—such as mobile apps and live chat.
Improve or migrate customers away from low-scoring, high-usage channels (e.g., desktop web, call centers).

3. Optimize Digital and Assisted Channels

Enhance digital journeys to replicate the best aspects of personal service—authenticity, flexibility, and active listening—at scale.
Use AI and analytics to personalize experiences and proactively address customer needs.

4. Measure, Iterate, and Prove ROI

Track changes in CXGX scores over time to measure the impact of specific investments.
Link improvements in CXGX to customer growth, retention, and business performance.

Case Examples: CXGX in Action at UK Retail Banks

Neobanks Lead the Way: Neobanks with the highest CXGX scores have seen the largest net gains in customer numbers, demonstrating the power of digital-first, customer-centric experiences.
Live Chat as a Growth Lever: Banks that invested in high-performing live chat channels saw both improved CXGX scores and reduced operating costs compared to traditional call centers.
Mobile App Adoption: Banks that successfully migrated customers from lower-scoring desktop web experiences to high-scoring mobile apps achieved measurable increases in overall CXGX and future usage intention.

The Future of CX Measurement in Banking

The CX Growth Index is more than a metric—it’s a strategic tool for transformation. As banks continue to invest in digital channels, AI, and omnichannel experiences, the ability to rigorously measure and prioritize CX investments will be a key differentiator.

With CXGX, banking executives, CX leaders, and digital strategists can:

Move beyond NPS to a more actionable, predictive framework
Link CX investments directly to business growth and retention
Prioritize the channels and touchpoints that matter most to customers
Build a culture of continuous improvement and customer-centric innovation

Ready to unlock the growth potential of customer experience? Discover how Publicis Sapient’s CXGX can help your bank lead the next wave of digital transformation.