Link Placements in Email Newsletters

Effects on Click-Through Rate (CTR) and Visual Heuristics

Ashish Kumar & Jari Salo (2018) — Journal of Marketing Communications

Motivation and Core Puzzle

  • Digital Media Advantage: Improvements in digital media capabilities (interaction, engagement, mutual coordination) have expanded B2B/B2C communications.
  • The Attention Economy: Abundance of digital messages creates a severe scarcity of consumer attention (Simon 1971; Lanham 2006).
  • The Core Puzzle: Firms utilizing email marketing strategy frequently face disappointingly low click-through rates (CTR).
  • Research Question: How does the spatial location (or visual region of sight) of link placements in email newsletters dynamically influence recipients’ click interactions?

Main Contribution: Explores how spacing, positioning, and layout of digital contents affect human attention and click decisions by mapping CTR across four geometric visual quadrants.

Visual Heuristics & Hypotheses

  • Synthesizes theories of Visual Hierarchy and Spatial Processing:
    • SNARC Effect (Attentional-SNARC): Spatial-Numerical Association of Response Codes (Dodd et al. 2008). Reading habits (left-to-right) train the brain to prioritize left-side visual regions.
    • Gutenberg Diagram: Divides a visual layout into four quadrants:
      • Primary Focus Area: Top-Left (North-West)
      • Strong Fallow Area: Top-Right (North-East)
      • Weak Fallow Area: Bottom-Left (South-West)
      • Terminal Area (Call to Action): Bottom-Right (South-East)

The U-Pattern Click Hypothesis: Click-through rates will follow a U-shaped visual path: starting very high in the Top-Left (Primary Focus), flowing down the Left to the Bottom-Left (Weak Fallow), scanning across to the Bottom-Right (Terminal Area), and being lowest in the Top-Right (Strong Fallow).

Data and Methodology

Data Source: - Secondary panel data from Liana Technologies, using LianaMailer™ tool managing diverse B2B/B2C email marketing solutions. - Six-month duration (January 2012 – June 2012) from 12 unique companies across 4 countries. - Final Sample: 110 distinct email campaigns from 10 companies, filtered to guarantee that each campaign has at least one link in all four quadrants.

Key Descriptives: - Average Open Rate: ~20%; Average Click-Through Rate (CTR): 16%. - Unsubscription Rate: 0.22%; Average words in subject: 6; Average body words: 208.

Model Specification: - Since the dependent variable CTR is fractional (proportional), the study estimates a Generalized Linear Model (GLM) with a logit link and binomial family (with firm fixed effects):

\[CTR_{fet} = \alpha_f + \beta_1 UnSubRate_{fet} + \beta_2 OpenRate_{fet} + \beta_3 SubLen_{fet} + \beta_4 BodyLen_{fet} + \beta_5 NoImage_{fet} + \beta_6 NoLinks_{fet} + \beta_7 PageLen_{fet} + \beta_{8-11} ClickRegion_{fet} + \epsilon_{fet}\]

Empirical Results (Table 2)

  • Estimations from the GLM model confirm highly significant visual layout and email characteristics effects:
Variable Type Independent Variable Estimate Std. Error Significance
Visual Regions Top-Left (North-West Click Region) 0.2885 0.1062 \(p \le 0.01\)
(The U-Pattern) Bottom-Left (South-West Click Region) 0.2617 0.1214 \(p \le 0.05\)
Bottom-Right (South-East Click Region) 0.0467 0.0161 \(p \le 0.01\)
Top-Right (North-East Click Region) 0.0223 0.0104 \(p \le 0.05\)
Email Activities Unsubscribe Rate -0.0767 0.0102 \(p \le 0.01\)
Open Rate 0.0054 0.0032 \(p \le 0.10\)
Email Design Subject Line Length -0.0121 0.0065 \(p \le 0.10\)
Body Word Length 0.0012 0.0005 \(p \le 0.01\)
Number of Links 0.0344 0.0186 \(p \le 0.10\)
Page Pixel Length -0.0002 0.0001 \(p \le 0.10\)
Number of Images 0.0012 0.0110 n.s.

Visualizing the U-Pattern

  • Clicks strictly follow the hypothesized U-pattern of visual reading flow:
    [START]                                       [END]
   Top-Left (NW)  ===========================>  Top-Right (NE)
     0.2885***                                    0.0223**
   (Highest CTR)                                (Lowest CTR)
         ||                                           /\
         || (Reading Down)                            || (Scanning Up)
         \/                                           ||
  Bottom-Left (SW)  =========================>  Bottom-Right (SE)
     0.2617**                                     0.0467***
  (Second Highest)                             (Terminal Area)
  • Top-down & Left-to-right: Readers begin in the Top-Left (Primary Focus) and scan down the Left column (capturing substantial attention).
  • The Terminal Area: The Bottom-Right quadrant acts as a terminal area where users expect closure, leading to moderate click-throughs.
  • Strong Fallow Area: The Top-Right corner is bypassed in rapid scanning, resulting in the lowest baseline click-throughs.

Strategic Design Implications

  • Primary CTAs: Position your most critical call-to-actions, subscription links, or hero product links in the Top-Left area.
  • Conversion Links: Align secondary CTAs along the Left column or place them in the Bottom-Right corner as terminal actions.
  • Avoid Strong Fallow Zones: Do not bury crucial conversion links or promotional offers in the Top-Right quadrant.

2. Keep Email Content Clutter-Free

  • Longer subject lines (\(\beta = -0.0121\)) and excessive vertical page length (\(\beta = -0.0002\)) significantly depress CTR. Keep campaigns concise and focused.
  • Images (\(\beta = 0.0012\), n.s.) do not statistically increase clicks. Limit visual noise to prevent cognitive “action dilemma.”

Citation: Kumar, A., & Salo, J. (2018). Journal of Marketing Communications, 24(5), 535-548. DOI: 10.1080/13527266.2016.1147485