Email Design & Consumer Choice

The Problem

• Email marketing is a $5.2B+ market, but effectiveness depends critically on design
• Most research focuses on simple “Open” or “Click” rates in isolation
• The Gap: We don’t know the relative impact of Opening, Clicking, and Reopening on actual individual-level spending behavior

Research Objective

“Quantify the effects of design elements on three engagement levels—Open, Click, Reopen—and their subsequent impact on spending.”

Key Metrics

• Open — First viewing of the email
• Click — Interacting with a link
• Reopen — Returning to view the email again

Information Processing Theory

• Design cues either simplify or complicate content filtering
• Information Overload: Larger emails and longer subject lines create cognitive friction
• Visual Anchors: Banners and links act as focal points to reduce perceived complexity

Conceptual Hypotheses (-/+)

• H1 Length (-): Long subject lines reduce engagement (perceived as spam/clickbait)
• H2 Size (-): High-volume content leads to overload
• H3 Links (+): Unique links facilitate “value co-creation”
• H4 Banners (+): Act as “atmospheric cues” to draw action

Data Integration

• Individual-level consumer behavior tracked across months
• Matched actual email exposure (received/opened/clicked) with real-world spending at the store
• Situational Factors: Modeling of loyalty, integrated media (catalogs), and timing

Econometric Approach

• Heckman Correction Model: Accounts for selectivity bias (Clicks/Reopens only happen after an Open)
• Simulation: Testing the “threshold” where the relative value of reopening vs. opening shifts

The Engagement Hierarchy

Ranking of impact on Purchase Volume:

1. Email Clicks (Highest Impact)
2. Email Reopen (Second-Highest)
3. Email Open (Lowest Impact)

Clicks and reopens represent “higher-level commitment” that significantly outperforms mere curiosity (opening).

Threshold Discovery

• Low Open Prob: Focus on encouraging Reopening to drive the most sales
• High Open Prob: The relative value of the initial Opening grows larger than reopening
• The Ideal Outcome: Consumers who indulge in all three actions—Opening, Clicking, and Reopening—spend the most

Theoretical Contributions

• Demonstrates the “reopen” action as a vital but overlooked stage of the funnel
• Highlights “media multiplexing”—reinforcing email with other channels (catalogs) increases spending

Strategic Takeaways

• Deepen Engagement: Don’t stop at the Open; design calls-to-action that drive Clicks and Reopens to maximize ROI
• Design for ROI: Balance subject line conciseness with visual elements (banners) that facilitate quick processing
• Segmented Strategies: If open rates are low, focus follow-up tactics on those likely to revisit the email