When a keyword performs well, the instinct is often to raise your bid and chase more traffic. But Amazon’s Impression Share report reveals a critical insight: if you already own most of the available impressions on a search term, bidding higher won’t get you more clicks—it will just cost you more money per click.
The Impression Share Signal
- What it shows: The percentage of total available impressions you’re capturing on a search term, aggregated across all campaigns in your account that receive clicks on it.
- The threshold rule: If your impression share is above ~80% (adjust to your preference), there is minimal additional traffic to be won on that term.
- The risk: Raising bids when you already dominate impression share means you’re paying more without gaining volume—especially risky if Amazon’s auction mechanics include hidden reserves or soft floors, as alleged in recent FTC litigation.
Why This Matters Now
Amazon’s ad auction is under regulatory scrutiny. The FTC alleges the platform inserts artificial competition (“soft reserves”) that inflate your effective cost per click beyond what a true second-price auction would charge. In a genuine second-price auction, bidding $1.50 when your nearest competitor bids $1.00 costs you only $1.01. But with hidden reserves, you may pay $1.31 or more—and if you’re already capturing 80%+ of impressions, that overpay buys you zero additional volume.
How to Use This Data
- Before raising bids: Pull your Impression Share report and check your current share on the keyword.
- For exact and phrase matches especially: High impression share is common; verify before bidding up.
- Track bid changes over time: Use daily-level Impression Share data to measure the actual impact of bid adjustments. A 20% drop in impressions after a bid cut could be entirely bid-driven, or partially seasonal—impression share isolates the true cause.
- Reverse the logic: Confirm that bid increases do move impression share; if they don’t, you’ve found a keyword where you’re already saturated.
How Squatio helps
When you’re running PPC, decisions about bid strategy should rest on solid data about keyword saturation and competitive positioning. Squatio Optimize (PPC intelligence) gives you visibility into your keyword performance and competitive landscape, so you can spot which terms are already capturing maximum available traffic before you waste budget chasing impressions that don’t exist. Sellers who track impression share trends over time catch waste faster and allocate their budget to keywords with real upside remaining.
Have you tracked your own impression share on high-performing keywords, and did it change your bid strategy? Or are there keywords where you noticed bid increases weren’t moving share or volume?
Source: Reddit