What Is a Percentage Point Change and Why Does It Matter in Placement-Level Bid Automation?

In ad performance reporting and bid automation, small terms often carry big implications. One of the most misunderstood among them is the difference between a percentage change and a percentage point change.

At first glance, they may look interchangeable. But when you’re adjusting placement-level bidding rules—say, reacting to a drop in Top of Search impressions—the distinction becomes critical.

A percentage point change refers to the absolute difference between two percentages. For example, if your Top of Search impression share moves from 30% to 35%, that’s a 5 percentage point increase. It’s not a 16.6% jump. That may seem like a technicality, but it’s the kind of detail that can completely change how your automations behave.

This guide breaks down what percentage point changes really mean, where they apply inside your Amazon Ads automation workflows, and why understanding them ensures your rules trigger at the right time—and for the right reason.

What is a Percentage Point?

A percentage point (pp) refers to the absolute difference between two percentages. 

It’s used to describe the change from one percentage to another without considering the original value as a base.

 In other words:

• A change from 30% to 40% is a 10 percentage point increase, not a 33% increase.
  
• It’s absolute, not relative.

Example: Understanding the Difference

Let’s say you’re tracking On-Time Arrival (OTA) for your logistics performance:

Percentage Point Change

80% – 70% = +10 percentage points

This simply means your OTA improved by an absolute 10-point increase.

Relative Percentage Change

Relative percentage increase = (10 / 70) × 100 = ~14.3%

So while the percentage point change is 10, the relative increase is about 14.3%. These numbers serve different purposes and shouldn’t be confused.

Why It Matters in Placement-Level Automation

In automated bidding or performance reporting, tools often show percentage point changes when evaluating shifts in placement distribution or conversion rates. For example:

• Your Top of Search impressions went from 25% to 35%.
  
• That’s a 10 percentage point increase, not a 40% increase.
  
• If rules are set to trigger based on a specific change (e.g., “Increase bid if Top of Search drops by 5 percentage points”), understanding this difference is essential to interpreting the change correctly.

Use Cases in Advertising Platforms

• Performance Automation Rules: Trigger bid increases or decreases when a percentage point change crosses a threshold.
  
• A/B Testing Placements: Measure how different placements impact CTR or CVR in absolute terms.
  
• Trend Analysis: Compare impression share or conversion rates over time.
  

Ready to get started?

A percentage point change helps you understand how metrics shift in absolute terms, which is often more intuitive when setting thresholds for bid automation or analyzing ad placements.

Knowing whether you’re looking at a 10% increase or a 10 percentage point increase can mean the difference between an optimized campaign and a misinterpreted result.

Tip: Next time you’re reviewing placement data or automation reports, check whether the platform reports percentage points or percent changes—because they don’t mean the same thing!