Metrics Every Amazon Seller Should Track: A Complete Guide to Boost Sales, Profitability, and Inventory Velocity

Are You Tracking the Metrics Every Amazon Seller Should Track?

Running a profitable Amazon store today isn’t just about having great products. It’s about focusing relentlessly on the right data. Seasoned sellers know that metrics every Amazon seller should track are the compass guiding growth. By monitoring key KPIs (sales, conversion, inventory, advertising, and customer health), you can spot issues early and double down on what’s working. Industry experts even highlight six critical metrics, from ad spend efficiency (TACoS) to inventory performance (IPI), that can “make or break” your Amazon business. In this guide, we answer the following questions: which metrics matter, why they matter, and how to calculate or improve them.

Understanding these KPIs will help you optimize listings, avoid stockouts, and boost profitability. For example, using Amazon’s Search Query Performance Report can uncover high-converting keywords. Similarly, advanced advertising metrics like TACoS and ACoS reveal if your ad campaigns truly drive growth. We’ll break down each essential category below.

Key Amazon Seller Metrics and Why They Matter

Every Amazon seller’s dashboard should include the metrics below. In each section, we’ll explain what to track, why it matters, and how to calculate or improve it.

Sales & Conversion Metrics

These metrics reveal how well your products sell and convert browsers into buyers. Monitor them to understand demand, pricing efficiency, and listing appeal.

1) Sales Velocity

Units sold per time period. This shows how fast your products are selling relative to competitors. High velocity means strong demand; Amazon’s Buy Box algorithm favors fast-moving items. How to use it: Track week-over-week velocity. If a product’s velocity suddenly drops, check for lost Buy Box or new competition.

2) Gross vs. Net Sales

Gross sales are your total Amazon revenue before fees, while net sales are what you keep after Amazon’s referral, FBA, and other fees. The difference (often 15–30%) represents fees and returns. For example, if your gross sales are \$100K but net sales are only \$70K, you’re losing 30% to fees/returns. Action: Use your Seller Central reports to calculate these and identify unusually high fees.

3) Average Order Value (AOV)

The average spend per order. Calculate AOV as Total Sales ÷ Number of Orders. Higher AOV means each customer spends more. Typical AOV varies by category (many consumer goods see \$25–50). Improve it: Bundle products or add complementary items to raise the average cart size. Amazon’s “Frequently Bought Together” feature can help upsell.

4) Conversion Rate (Unit Session Percentage)

The percentage of customer sessions that end in a purchase. In Amazon reports, this is often called Unit Session Percentage. Formula: Units Ordered ÷ # of Sessions. A healthy conversion rate on Amazon is typically 8–12% overall (category-dependent; e.g., 10–15% in Health/Household). If your conversion is low (<8%), improve your main image, pricing, and review count before spending more on ads. (By the way, Amazon’s Search Query Performance Report can help find keyword-specific conversion rates, as discussed in our blog.

5) Buy Box Percentage

The share of page views where your offer was the Buy Box winner. Since about 80% of Amazon purchases go through the Buy Box, this metric is critical. Amazon considers price, availability, seller rating, and sales velocity when assigning the Buy Box. If your Buy Box rate drops, check for price undercuts or inventory issues.

Pro Tip: Even a small change in Buy Box share can dramatically affect sales.

Inventory & Logistics Metrics

These metrics show how efficiently you manage stock. Amazon penalizes both overselling and overstocking, so keep a close eye here.

1) Inventory Performance Index (IPI)

Amazon’s efficiency score (0–1000) for how well you manage FBA inventory. An IPI above ~500 means smooth operations; below 450 risks storage limits. It factors in sellthe -through rate, in-stock rate, and excess inventory. To improve IPI: Quickly clear out aged or slow-moving inventory (e.g., run promotions on ASINs with low sales).

2) Stockout Rate

The percentage of time a SKU is out of stock. Every stockout costs missed sales and damages your ranking (Amazon assumes items are unpopular when out of stock). Benchmark: Keep stockouts under ~2% for key products. Action: Automate reorder points, don’t wait until the last week of supply. Use lead-time forecasts (e.g., reorder when 30 days of inventory remain).

3) Days of Inventory (Days of Supply)

How long current inventory last at the current sales pace? Optimal days-on-hand depend on the product (many fall in 30–60 days). Calculation: Current Stock ÷ Average Daily Sales. If you consistently have >90 days of stock, you’re tying up cash and incurring storage fees. On the flip side, too few days’ supply risks frequent stockouts. Find a balance.

4) Inventory Velocity

How quickly inventory turns into sales. In simple terms, high velocity means products are selling and replenishing fast, freeing up cash flow. Inventory velocity is not just turnover rate; it’s a focus on selling the right products at the right pace. Why it matters: Faster inventory cycles improve cash flow and reduce carrying costs. For example, Shopify brands increased cash flow by rotating stock quickly. To boost velocity, focus marketing on your best-sellers and offload slow items (lightning deals or clearances).

Advertising & Marketing Metrics

With Amazon’s ad spend growing rapidly, carefully managing ad metrics is a must. These KPIs tell you if your PPC and marketing efforts are truly profitable.

1) Total Advertising Cost of Sales (TACoS)

Ad spend as a percentage of total sales (including organic). TACoS shows if ads are growing your overall business or just shifting existing sales from organic to paid. Formula: (Total Ad Spend ÷ Total Sales)×100. For established brands, a healthy TACoS is often ~8–12%; new product launches may run 15–20%. If TACoS is rising but overall sales aren’t, your brand is becoming too reliant on ads.

2) Advertising Cost of Sales (ACoS) & Return on Ad Spend (ROAS)

ACoS measures ad spend ÷ ad-driven sales (lower ACoS = better), whereas ROAS is ad-driven sales ÷ ad spend (higher ROAS = better). For example, good Sponsored Product campaigns often have ACoS around 15–30% (ROAS 3–7x). Track campaign ACoS by product; if ACoS exceeds these benchmarks, pause wasted spend and reallocate budget to winners.

3) Click-Through Rate (CTR)

The percentage of ad impressions that result in clicks. A higher CTR means your ad text/image is relevant. On Amazon, typical CTRs are in the 0.3–0.5% range. If your CTR is unusually low, experiment with different titles, images, or ad copy.

4) Ad Conversion Rate (CVR)

Of those clicks, how many convert to sales (similar to the above “conversion rate,” but for ads)? Amazon's average CVR is high (generally 9–12% is average, 13–15% excellent). If your ads get clicks but poor sales, your targeting or listing relevancy may be off.

5) Keyword Performance (Search Queries)

Track metrics like impression share, click share, add-to-cart share, and purchase share for search queries. For instance, using Amazon’s Search Query Performance Report lets you spot high-intent keywords with low coverage. We cover this in our blog on keyword analysis. Target keywords that show high add-to-cart or purchase share but low impression share; these are big opportunities.

Managing all this data can be complex. That’s why many sellers partner with Amazon PPC experts; they can monitor ad KPIs, optimize bids/keywords, and ensure your metrics (CTR, CVR, ACoS, TACoS) drive real profit.

Customer & Account Health Metrics

Amazon enforces strict seller performance standards. These metrics protect your account and reflect customer satisfaction:

1) Order Defect Rate (ODR)

The percentage of orders with a defect (negative feedback, A-to-Z claim, or chargeback). Amazon’s threshold is <1% (aim below 0.5% for safety). A rising ODR is a red flag; if it nears 0.75%, pause all promotions and fix fulfillment issues until it drops.

2) Late Shipment Rate & Delivery Metrics

Often included in ODR, keep late shipments under 4% and follow through on shipping promises. If Amazon notices many late or cancelled orders, it will restrict your sell-through and hurt your Buy Box chances.

3) Seller Feedback Rating

Your seller feedback average (stars and positive %). Aim to stay above 4.7 stars with >95% positive feedback. Amazon now weighs recent feedback more heavily, so even a few bad reviews can quickly pull you down. Encourage satisfied buyers to leave feedback and respond promptly to any issues.

4) Customer Reviews (Product Rating)

While not exactly account health, product review scores impact conversion. Track your average product rating (star) and review count. Products with ratings below 4.0 or few reviews will have much lower conversion rates. (Improve this via follow-up emails, “Request a Review”, and exceptional service.)

5) Customer Acquisition Cost (CAC) vs. Lifetime Value (LTV)

Are you making money or just burning cash on ads and promotions? Calculate your true CAC by adding all costs to acquire a customer (ad spend, discounts, brand development, etc.). Then compare to the customer’s lifetime value (repeat purchases). Sustainable businesses have an LTV of at least 3× CAC. If not, either cut acquisition costs or increase retention/pricing.

6) Return Rate

The percentage of orders that are returned. High return rates (beyond typical category norms) eat into margins and may indicate listing inaccuracies or product issues. Monitor this in your Seller Reports and investigate spikes.

By keeping these metrics within healthy ranges, you protect your account from Amazon penalties and build long-term profit. For instance, low ODR and strong feedback help you consistently win the Buy Box and avoid account suspensions.

Inventory Velocity and eCommerce Success

Inventory velocity, how fast products move and are replenished, is a secret weapon for Amazon's growth. High velocity means you quickly turn stock into revenue, which improves cash flow and agility. Faster-moving inventory keeps cash unfrozen (you’re not paying warehouse fees on stale stock) and lets you reinvest in new products or marketing. For example, one merchant increased cash flow dramatically by focusing on top-selling SKUs and cycling them rapidly.

On the other hand, slow velocity ties up capital and inflates carrying costs[19]. Overfilled warehouses mean paying unnecessary storage fees (especially Amazon’s long-term storage surcharges).

How to calculate inventory velocity?

One simple formula is Sales in a period ÷ Average Inventory (over the same period). The higher the result, the faster your turnover. You can also track days of inventory sold. In practice, improving velocity means: Prioritize marketing for your best sellers.

• Run promotions (bundles, coupons, lightning deals) to move older stock.

• Streamline your supply chain (shorter lead times, smaller replenishments) to restock quickly.

Investing in inventory planning and agile replenishment is key. Many successful sellers use forecasting tools and 3PL partners to keep stock flowing.

Push Inventory Velocity Boundaries with My Brand Genius

At My Brand Genius, we empower Amazon sellers to take control of their inventory velocity through smart analytics, automation, and data-backed decision-making. Managing your Amazon business isn’t just about tracking numbers; it’s about understanding how every metric connects to cash flow, profitability, and growth.

Our experts help you monitor and improve the metrics every Amazon seller should track, from IPI scores and sell-through rates to TACoS, conversion rate, and AOV. Using cutting-edge tools and our proprietary strategies, we help sellers:

• Optimize inventory turnover to maintain high sales velocity without overstocking.

• Automate KPI tracking so you can make real-time decisions on pricing, advertising, and replenishment.

• Improve profitability by aligning advertising data with actual inventory performance.

• Eliminate guesswork using clear dashboards and performance reports designed for Amazon sellers.

When you partner with My Brand Genius, you gain a data-driven roadmap to push your inventory performance beyond standard benchmarks. That means better Buy Box share, fewer stockouts, and higher ROI, all while maintaining operational efficiency.

Pro Tip: Combine inventory analytics with your marketing performance metrics to find the sweet spot where ads fuel inventory velocity, not oversupply.

Quick Reference: Amazon Seller Metrics Table

Metric	What it Measures	Target/Benchmark
Conversion Rate (Unit Session %)	% of listing views that convert into a sale.	Varies by category; ~8–12% general (13%+ is excellent).
Average Order Value (AOV)	Avg revenue per order.	Higher is better; common range \$25–50.
Sales Velocity	Speed of sales (units/time) vs. competitors.	Monitor trends week-to-week (no fixed benchmark).
Buy Box Percentage	% of potential sales where you won the Buy Box.	Aim as high as possible (~90%+ on your main ASIN).
Inventory Performance Index (IPI)	Amazon’s score for your inventory management.	500+ (stay above 450 to avoid limits).
Stockout Rate	% of time products are out of stock.	Keep <2% for main SKUs.
Total Advertising Cost of Sales (TACoS)	Total ad spend ÷ total sales.	8–12% for mature brands; up to 15–20% for launches.
Advertising Cost of Sales (ACoS)	Ad spend ÷ sales from ads.	Varies by campaign: 15–30% for Sponsored Products.
Click-Through Rate (CTR)	% of ad impressions that got clicks.	Aim 0.3–0.5%+ on Amazon.
Order Defect Rate (ODR)	% of orders with negative marks (late, cancel, neg FB).	<1% (Amazon’s limit; ideally <0.5%).
Seller Feedback Rating	Avg star rating from customers.	4.7+ stars with >95% positive.
CAC vs. LTV	Ratio of Customer Acquisition Cost to Customer Lifetime Value.	LTV ≥ 3× CAC for profitability.

Table: Core Amazon seller metrics, what each measures, and typical targets or benchmarks. Use this as a quick checklist for your store.

Summing Up

Tracking the right metrics is like having a GPS for your Amazon business. By consistently monitoring sales conversion, inventory levels, ad spend, and customer health, you can steer your store in the most profitable direction. Start by downloading your sales and inventory reports, setting up alerts for red flags (like rising ODR or falling IPI), and revisit your metrics weekly. Over time, use these numbers to test and learn: run a promotion when stock piles up, tweak listings when conversion lags, or pause ad campaigns that aren’t yielding enough sales.

Remember, metrics aren’t just numbers; they’re signals. A sudden drop in conversion rate might mean a listing issue; a spike in stockout rate suggests you need faster restock. Use our [metrics action plan] as a guide: establish baselines for TACoS, AOV, and other KPIs, then improve them one by one. With each improvement, you’ll not only boost sales but also build a healthier, more sustainable Amazon business.

Frequently Asked Questions

How often should I monitor my Amazon metrics?

Set a routine. Check critical account-health metrics (ODR, IPI, Buy Box win rate) weekly. Monitor advertising metrics (ACoS, TACoS, CTR) every few days when campaigns are active. Perform a comprehensive review of all metrics at least monthly to spot trends.

What’s the difference between ACoS and TACoS?

ACoS (Advertising Cost of Sales) is ad spend ÷ revenue from ads – it measures the efficiency of individual campaigns. TACoS (Total Advertising Cost of Sales) is ad spend ÷ total sales (organic + ads). In short, ACoS looks at your ads in isolation, while TACoS shows the bigger picture. A low ACoS with a high TACoS means you’re relying too much on ads to make sales.

What’s a good Amazon conversion rate?

It varies by category. The current industry data suggests 8–12% as a healthy benchmark. Some categories can be higher (e.g., 10–15% in Home & Kitchen). Use Amazon Brand Analytics (if enrolled) to see category averages. If your rate is below these, work on listing quality: better images, competitive pricing, more reviews, and targeted ads to boost relevancy.

How is inventory velocity calculated, and why is it important?

Inventory velocity is typically sales during a period divided by the average inventory held. It essentially tells you how many times you “turn” your stock. High velocity keeps cash flowing – when products fly off the shelves, your money isn’t locked up. This improves cash flow, reduces storage fees, and lets you reinvest in growth. If your velocity is low, you’re carrying dead stock, which hurts liquidity.

Should I track the same metrics for every product?

Not necessarily. New product launches often focus on search rank, conversion rate, and review velocity. Mature products should emphasize profitability metrics (TACoS, net margin) and inventory turnover. Tailor your dashboard by product lifecycle. Regardless, keep an eye on core health metrics (ODR, IPI, Buy Box) across your account at all times.