Retail & Consumer Goods: E-Commerce and Omnichannel Strategy Cases

E-commerce now accounts for over 20% of total retail sales globally, and that share is still climbing. For consulting candidates, this means retail cases increasingly center on digital channels, omnichannel integration, and the economics of fulfillment — not just traditional store operations. Based on our analysis of 800+ case interviews, roughly one in three retail cases now includes an e-commerce or omnichannel component.

This guide covers the five most common e-commerce and omnichannel case patterns you will encounter, with practical frameworks and the key metrics interviewers expect you to use.

Why E-Commerce Cases Are Different from Traditional Retail

Traditional retail cases focus on store-level profitability, foot traffic, and inventory turns. E-commerce cases introduce a fundamentally different cost structure: customer acquisition cost (CAC) replaces location-based foot traffic, fulfillment cost per order replaces store operating cost, and lifetime value (LTV) becomes the central profitability metric.

The shift matters because candidates who default to a traditional retail framework — analyzing same-store sales or rent optimization — will miss the core issue in an e-commerce case.

The Five Core E-Commerce and Omnichannel Case Patterns

Based on our experience coaching candidates across MBB and Big Four firms, e-commerce cases cluster into five recurring archetypes:

mindmap
  root((E-Commerce &\nOmnichannel Cases))
    DTC Launch
      Channel economics
      Brand control
      CAC payback
    Marketplace vs.\nOwned Channel
      Commission structure
      Data ownership
      Logistics control
    Last-Mile\nFulfillment
      Delivery cost
      Speed vs. cost
      Store-as-hub
    Channel Conflict
      Pricing parity
      Cannibalization
      Partner management
    Digital Customer\nAcquisition
      CAC optimization
      Conversion funnel
      Retention strategy

Pattern 1: DTC (Direct-to-Consumer) Launch

A CPG or branded manufacturer wants to sell directly to consumers online, bypassing traditional retail partners. The interviewer is testing whether you can quantify the trade-off between higher margins and the cost of building a direct channel.

Key questions to structure around:

• What is the margin uplift from eliminating the wholesale/retail markup (typically 40–60% of retail price)?
• What CAC is sustainable given the product’s average order value and repeat purchase rate?
• How will existing retail partners react, and what is the revenue at risk from channel conflict?

In our experience, the strongest candidates build a simple unit economics model: gross margin per DTC order minus CAC minus fulfillment cost, then compare it to the current wholesale margin. If the DTC contribution margin does not exceed the wholesale margin within 18–24 months, the case typically points toward a hybrid model rather than a full DTC pivot.

Pattern 2: Marketplace vs. Owned Channel

A retailer or brand is deciding whether to sell through a third-party marketplace (Amazon, Tmall) or invest in its own e-commerce platform. This tests your ability to evaluate trade-offs between reach and control.

Framework for comparison:

The best answers recognize that this is rarely an either/or decision. Most brands pursue a portfolio approach — using the marketplace for discovery and volume, while driving high-value customers to the owned channel for repeat purchases and higher margins.

Pattern 3: Last-Mile Fulfillment Economics

A grocery chain or retailer wants to offer same-day or next-day delivery. The case centers on whether the economics work and which fulfillment model to adopt.

Three fulfillment models to compare:

1. Store-as-hub: Picking from existing store inventory. Low fixed cost, but higher pick cost per order and limited SKU availability.
2. Dark store / micro-fulfillment center: Dedicated facility optimized for online orders. Higher fixed cost, but 3–5x faster picking and better availability.
3. Central distribution center: Traditional DC with last-mile delivery partner. Lowest per-unit cost at scale, but slower delivery speed.

The key metric is cost per delivered order, which typically ranges from $8–15 for store-as-hub to $3–7 for automated micro-fulfillment at scale. Interviewers expect you to recognize that delivery fees rarely cover true fulfillment cost, so the question becomes: does the incremental customer lifetime value justify the subsidy?

Pattern 4: Channel Conflict and Pricing Parity

A consumer goods company is seeing friction between its online and offline channels — retail partners complain about being undercut, or the company’s own stores compete with its website. This pattern tests strategic thinking about stakeholder management alongside quantitative analysis.

Typical resolution approaches:

• Price parity with differentiated assortment: Same prices across channels, but offer online-exclusive SKUs or bundles
• Channel-specific promotions: Different discount mechanisms (e.g., in-store loyalty rewards vs. online free shipping thresholds)
• Geographic segmentation: Online channel focuses on markets without physical retail presence

The analytical crux is calculating net cannibalization: what percentage of online sales would have occurred in-store anyway? In our analysis, this ranges from 20–40% for apparel and 50–70% for commodity goods. Subtracting cannibalized sales from the online revenue growth gives you the true incremental contribution.

Pattern 5: Digital Customer Acquisition and Retention

A retailer’s online growth has stalled or CAC is rising faster than revenue. The case focuses on diagnosing where in the digital funnel the problem lies and recommending optimization strategies.

Diagnostic framework — the conversion waterfall:

flowchart LR
    A[Impressions] -->|CTR| B[Site Visits]
    B -->|Browse-to-cart| C[Add to Cart]
    C -->|Cart-to-checkout| D[Checkout]
    D -->|Checkout completion| E[Purchase]
    E -->|Repeat rate| F[Repeat Purchase]

At each stage, benchmark against industry averages:

• CTR (paid search): 2–4% for retail
• Browse-to-cart: 8–12%
• Cart abandonment: 65–75% is typical; below 60% is strong
• Repeat purchase rate: 25–35% within 12 months for general retail

The insight interviewers look for is whether the problem is a top-of-funnel issue (not enough qualified traffic) or a mid/bottom-funnel issue (poor conversion or retention). The solutions differ dramatically: top-of-funnel problems call for channel mix optimization, while conversion problems require UX, pricing, or assortment fixes.

Key Metrics to Know Cold

Walking into any retail e-commerce case, you should be comfortable with these metrics:

Connecting E-Commerce to Broader Retail Frameworks

E-commerce cases do not exist in isolation. In a real interview, you may start with an omnichannel question and pivot to profitability analysis when the unit economics do not work, or move into market entry when evaluating a new geography for online expansion.

For foundational retail frameworks, see our Retail Industry Deep Dive. If your case involves brand portfolio decisions for online channels, the Consumer Goods & CPG Cases guide covers the relevant frameworks. And for cases that involve pricing decisions across channels, review the Pricing Strategy Cases guide.

Practice with retail industry cases and consumer goods cases in our case library to build fluency with these patterns. For real-time feedback on your e-commerce case delivery, try our AI Mock Interview — it can simulate omnichannel scenarios and test your ability to structure these digital-first problems under time pressure.

Key Takeaways

• E-commerce cases require a different analytical toolkit than traditional retail — lead with unit economics (LTV, CAC, contribution margin), not store-level P&L
• The five core patterns are DTC launch, marketplace vs. owned channel, last-mile fulfillment, channel conflict, and digital customer acquisition
• Most omnichannel cases are not either/or decisions — the best answers build a portfolio approach that balances reach, margin, and control
• Always quantify cannibalization when online and offline channels overlap — the net incremental revenue is what matters
• Benchmark your funnel metrics against industry averages to quickly pinpoint where the problem lies
• Fulfillment economics are the hidden driver of e-commerce profitability — delivery fees rarely cover true cost, so frame it as an LTV investment