Why has the click-through rate for Criteo's display ads dropped 15% in the last week?

Introduction

The recent 15% drop in click-through rate (CTR) for Criteo's display ads is a significant issue that requires immediate attention. As we analyze this product challenge, I'll employ a systematic framework to identify, validate, and address the root cause while considering both short-term fixes and long-term strategic implications.

I'll approach this problem by first clarifying the context, then ruling out external factors before diving deep into the product ecosystem, metric breakdown, and data analysis. From there, I'll form hypotheses, conduct root cause analysis, and propose validation methods and solutions.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking there might be a recent change in ad placement. Has there been any modification to ad positioning on partner websites in the last week?

Why it matters: Ad placement significantly impacts visibility and CTR. Expected answer: No recent changes to ad placement. Impact on approach: If there were changes, we'd focus on reverting or optimizing placement.

• Considering user segments, I'm curious about the distribution of this CTR drop. Is the 15% decrease uniform across all user segments, or are certain groups more affected?

Why it matters: Helps identify if the issue is global or segment-specific. Expected answer: The drop is not uniform; some segments are more affected. Impact on approach: We'd prioritize investigating the most affected segments.

• Given the abruptness of the change, I'm wondering about technical issues. Have there been any reported problems with ad serving or tracking in the past week?

Why it matters: Technical glitches can cause sudden metric changes. Expected answer: No major technical issues reported. Impact on approach: If technical issues are confirmed, we'd prioritize fixing those first.

• Thinking about external factors, has there been any significant change in the competitive landscape or major world events that could influence user behavior?

Why it matters: External events can dramatically impact ad performance. Expected answer: No major external events noted. Impact on approach: If external factors are at play, we'd need to adapt our strategy accordingly.