How to Compare Amazon Ads Performance with the Previous Period

Comparing Amazon Ads performance with the previous period helps sellers and marketers detect growth or issues in their campaigns by examining key metrics like spend, sales, ROAS, and ACoS. Structured analysis allows for actionable insights, clearer benchmarking, and improved ad strategy, especially when using visual dashboards and consolidated reports.

Track, analyse, and benchmark results for better campaign insights

Monitoring the progress of your Amazon advertising efforts requires regularly comparing your recent results against past performance. This guide provides a practical step-by-step workflow to ensure your period-over-period analysis is crucial for optimizing ad spend and identifying new opportunities or concerns. Whether you manage one brand or multiple marketplaces, consistent analysis leads to smarter business decisions.

What You'll Need

Amazon Ads Dashboard by Todoza: A dashboard that aggregates Amazon Ads reports to monitor key advertising metrics across accounts and periods.
Recent and previous period Amazon Ads reports (CSV/XLSX/TSV exported or scheduled emails)

Visualise Performance with Connected Dashboards

Automated dashboards present historical and current period data in clear graphs and tables, helping you easily identify positive or negative trends. Connecting your Amazon Ads accounts enables streamlined comparison of KPIs and wasted spend, saving time on manual spreadsheets and reducing reporting errors.

Step 1: Define the Time Periods to Compare

Set a consistent time frame for your analysis—commonly week-over-week, month-over-month, or custom ranges that matter for your business. Ensure that you choose matching lengths and types of days (e.g., Monday–Sunday vs. previous Monday–Sunday) to avoid seasonal or day-of-week distortions. Setting boundaries up front helps guarantee you are comparing truly equivalent data sets.

Step 2: Collect and Organise Your Data

Aggregate and organise your ad data from Amazon reports. Download the required CSV, XLSX, or TSV files for both periods, or use tools that automate this step via scheduled emails. A specialised dashboard like Amazon Ads Dashboard by Todoza can merge these inputs and display performance data side by side, making the process much clearer and more efficient, especially if you are managing multiple brands or locales.

Step 3: Compare Key Metrics Across Periods

Compare the same KPIs across periods, focusing on metrics such as spend, sales, impressions, click-through rate (CTR), return on ad spend (ROAS), advertising cost of sales (ACoS), and wasted spend. Visual dashboards allow you to easily see changes and calculate trends like percentage growth or decline in each metric. Pay close attention to significant shifts, as they may signal underlying changes in your campaigns or the wider marketplace.

Step 4: Analyse Trends and Spot Issues

Identify trends and spot performance drops by reviewing week-over-week or month-over-month variations. A dashboard that highlights declines and flags risks can make it much easier to detect negative trends before they affect your bottom line. Look for consistent improvements or emerging issues in metrics like conversion rates and wasted spend, as these often correspond to actionable insights for your ad strategy.

Step 5: Investigate and Take Action

Investigate anomalies or flags, such as sudden drops in ROAS or spikes in wasted spend. Cross-reference flagged periods with changes in campaign settings, budget allocations, or promotional events. Use your findings to refine your ad strategies, adjust budgets, or target new keywords to improve future campaign performance based on clear data-driven evidence.

Common Pitfalls and Pro Tips

Be consistent: Always compare matching date ranges to eliminate seasonality bias.
Avoid data gaps by regularly scheduling exports or connecting tools that aggregate reports automatically.
Look beyond vanity metrics—focus on true business outcomes like sales growth and reduction in wasted spend, not just increases in clicks.
Double-check for one-off events (like Prime Day) that can skew short-term comparisons.

Spot Trends and Risks Quickly

By highlighting significant changes in spend, sales, and efficiency metrics, a central dashboard like Amazon Ads Dashboard by Todoza draws attention to risks and opportunities. Proactive alerting helps inform your next moves for campaign optimization.