Seller Spy by Seller Assistant is a tool for monitoring Amazon competitors before they outpace you. It tracks catalog, brand, and pricing changes across every seller you’re watching, automatically.
Most wholesale sellers don’t miss opportunities because they’re not looking. They miss them because they’re looking in the wrong place – checking individual product pages one at a time while competitors quietly add winning brands, expand into new categories, and build their catalogs three steps ahead.
Seller Assistant’s Seller Spy runs the monitoring you’d normally do manually – new brands, added products, pricing shifts, catalog overlap – across every competitor you track, continuously. In minutes, you see exactly what’s changed and where the gaps in your own catalog are. You only chase the opportunities that are already proven.
What Is Seller Spy by Seller Assistant?
Seller Spy by Seller Assistant is an Amazon competitor monitoring tool that helps wholesale sellers, online arbitrage sellers, and dropshippers discover sourcing opportunities by tracking competitor activity. Instead of manually checking Amazon storefronts, sellers can monitor competitors’ catalogs, brands, products, and pricing changes from a single workspace, making it easier to identify new opportunities and stay ahead of market trends.
The tool provides competitor intelligence at multiple levels. Sellers can monitor market-wide activity through the Overview dashboard, manage tracked competitors in the Sellers dashboard, and analyze individual competitors in depth with the Seller Details page. Seller Spy highlights newly added brands and products, catalog changes, competitor activity, brand and category distribution, and catalog overlap with your own inventory, helping sellers uncover sourcing opportunities faster.
Seller Spy also integrates with other Seller Assistant tools to create a connected sourcing workflow. Sellers can launch Brand Analyzer to evaluate a discovered brand’s demand, competition, and resale potential, use AI Supplier Finder to locate manufacturers, distributors, and wholesalers, and continue product research in Price List Analyzer before making purchasing decisions.
Benefits of Seller Spy
Monitoring competitors is one of the most effective ways to uncover profitable sourcing opportunities on Amazon. Instead of manually checking storefronts and trying to spot changes yourself, Seller Spy automatically tracks competitor activity and organizes it into actionable insights. From discovering new brands to identifying gaps in your catalog, Seller Spy helps wholesale sellers, online arbitrage sellers, and dropshippers make faster, data-driven sourcing decisions and stay ahead of the competition.
Discover new sourcing opportunities
Identify brands and products competitors recently added to uncover profitable opportunities before they become widely adopted.
Monitor competitors automatically
Track competitor catalogs, pricing, brands, and product changes without manually checking Amazon storefronts.
Spot market trends earlier
See how competitors expand into new brands and categories to identify emerging sourcing trends and changing customer demand.
Identify gaps in your catalog
Compare your inventory with competitor catalogs to find brands and products you don’t yet carry.
Prioritize brand research
Focus on brands competitors actively sell and validate them with Brand Analyzer before investing time in supplier outreach.
Find suppliers faster
Launch AI Supplier Finder directly from Seller Spy to identify manufacturers, distributors, and wholesalers for promising brands.
Analyze competitor strategies
Review competitor catalog growth, brand portfolios, category distribution, and recent activity to better understand their sourcing approach.
Save time on competitor research
Replace repetitive storefront checks with automated monitoring and centralized competitor intelligence.
Make smarter sourcing decisions
Use real competitor data to validate opportunities, reduce guesswork, and prioritize products with proven market demand.
Connect your sourcing workflow
Move seamlessly from competitor monitoring to brand analysis, supplier discovery, product research, and purchasing within Seller Assistant platform.
What Seller Spy Shows
Seller Spy combines market intelligence, competitor analytics, brand insights, product tracking, and sourcing integrations to help sellers monitor competitors and uncover new opportunities. Instead of manually reviewing Amazon storefronts, the tool provides a complete view of competitor activity, catalog changes, brand portfolios, and product updates in one workspace.
Market activity and sourcing opportunities
The Overview dashboard gives sellers a snapshot of activity across all tracked competitors. It displays key metrics such as the number of tracked sellers, active competitors, new brands discovered, and products added over the last 30 days.
The dashboard also highlights sourcing opportunities with widgets showing competitor activity, the most active sellers, trending brands, and brands competitors carry that aren’t yet in your catalog. These insights help sellers identify market trends and prioritize research.
Competitor insights
The Sellers Dashboard provides a centralized view of every tracked competitor.
Each seller profile includes information such as:
- Marketplace
- Seller type
- Catalog size
- Products added during the last 30 days
- Brands added during the last 30 days
- Seller rating and review count
- Tracking date
- Last update
- Notes
These metrics help sellers identify fast-growing competitors, compare sourcing strategies, and decide which sellers deserve closer analysis.
Seller-level analytics
The Seller Details page provides a deeper look at each tracked competitor through the Insights, Brands, and Products tabs.
The Insights tab summarizes the competitor’s business by showing:
- Total products
- Total brands
- Seller rating and review count
- New brands added during the last 30 days
- Product and brand overlap with your catalog
- Products added and removed during the last 30 days
- Brand distribution
- Category distribution
- Seller information, including fulfillment model, shipping origin, and business details
These insights help sellers understand how competitors build their catalogs and identify opportunities to expand their own inventory.
Brand insights
The Brands tab provides a complete view of a competitor’s brand portfolio.
Sellers can switch between Current and New brands, search for specific brands, and filter results to display:
- All brands
- Brands already in your catalog
- Opportunity brands not yet in your catalog
This makes it easy to identify recently added brands, monitor competitor sourcing activity, and focus research on brands with the greatest potential.
Product tracking
The Products tab allows sellers to monitor both current inventory and catalog changes.
Available filters include:
- Current products
- Product changes
- Brand
- Category
- Keyword
- ASIN
For each product, Seller Spy displays details such as the product title, image, ASIN, brand, category, model number, notes, and change status. These filters help sellers investigate competitor catalogs, monitor inventory changes, and identify products worth sourcing.
Connected sourcing workflow
Seller Spy connects competitor monitoring with the rest of Seller Assistant. Sellers can launch Brand Analyzer to evaluate a discovered brand’s demand, competition, catalog depth, Amazon presence, and resale potential before contacting suppliers.
From there, they can use AI Supplier Finder to locate manufacturers, authorized distributors, and wholesalers associated with the brand, then continue product evaluation in Price List Analyzer to analyze profitability, ROI, competition, fees, and restrictions before purchasing inventory.
Continuous monitoring and exports
Seller Spy continuously tracks competitor catalog changes, allowing sellers to monitor new brands, product additions, removals, and updates over time. Product-level changes can be reviewed directly inside the platform or exported as a complete tracked seller dataset for offline analysis or team collaboration.
Seller Spy Use Cases
Seller Spy supports every stage of competitor research, from discovering new sourcing opportunities to validating brands and finding suppliers. Whether you’re a wholesale seller, online arbitrage seller, or dropshipper, Seller Spy helps you monitor competitor activity, identify profitable opportunities, and make sourcing decisions based on real marketplace data.
Discovering new sourcing opportunities
Use case
A seller wants to find profitable products and brands without spending hours searching Amazon manually.
Solution
Seller Spy tracks competitor catalogs and highlights newly added brands and products, helping sellers discover sourcing opportunities that have already been validated by other Amazon resellers.
Monitoring competitor activity
Use case
A seller wants to understand how competitors expand their catalogs and respond to market changes.
Solution
Seller Spy continuously tracks product additions, removals, pricing updates, and brand changes, making it easy to monitor competitor strategies over time instead of relying on one-time storefront reviews.
Identifying gaps in your catalog
Use case
A seller wants to expand their inventory but isn’t sure which products or brands they’re missing.
Solution
Seller Spy compares competitor catalogs with your own and highlights products and brands you don’t yet carry, helping you prioritize new sourcing opportunities.
Finding new brands to source
Use case
A seller wants to discover brands that successful competitors have recently started selling.
Solution
The Brands tab displays current and newly added brands, making it easy to identify promising brands and focus research on opportunities with proven marketplace demand.
Researching competitor products
Use case
A seller wants to see exactly which products a competitor recently added or removed.
Solution
The Products tab tracks catalog changes over time and lets sellers filter results by time period, status, brand, category, keyword, or ASIN to investigate specific opportunities.
Prioritizing competitors for research
Use case
A seller tracks dozens of Amazon competitors and wants to know which ones deserve the most attention.
Solution
The Overview and Sellers dashboards highlight active competitors, recent catalog growth, and sourcing activity, helping sellers focus on competitors driving the most market changes.
Validating brands before sourcing
Use case
A seller discovers a promising brand through competitor monitoring but wants to evaluate it before contacting suppliers.
Solution
Seller Spy integrates with Brand Analyzer, allowing sellers to assess demand, competition, catalog depth, Amazon presence, and resale potential without leaving their workflow.
Finding suppliers for competitor brands
Use case
A seller identifies a brand competitors sell but doesn’t know where to source it.
Solution
Seller Spy connects directly with AI Supplier Finder, making it easy to locate manufacturers, authorized distributors, and wholesalers associated with the brand.
Tracking long-term competitor trends
Use case
A seller wants to monitor how a competitor’s catalog evolves over weeks or months rather than reviewing occasional snapshots.
Solution
Seller Spy continuously records catalog changes, allowing sellers to identify recurring sourcing patterns, brand expansion, and long-term growth strategies.
Supporting team-based sourcing
Use case
A sourcing team needs a shared view of competitor activity and opportunities.
Solution
Tracked competitors, seller notes, and competitor insights are centralized in Seller Spy, making it easier for team members to collaborate, share findings, and coordinate sourcing efforts.
How Does Seller Spy Work?
Seller Spy follows a structured competitor research workflow that helps sellers move from monitoring Amazon competitors to discovering sourcing opportunities and validating them. Instead of manually checking storefronts, the tool collects competitor activity in one place, allowing you to monitor market trends, analyze seller catalogs, discover new brands and products, and continue your research with Brand Analyzer, AI Supplier Finder, and Price List Analyzer. This connected workflow helps you identify, evaluate, and source profitable inventory more efficiently.
Step 1. Start tracking competitors
Open Seller Spy from the Tools section in Seller Assistant and add the Amazon sellers you want to monitor.
Tracking competitors is the foundation of the workflow because Seller Spy begins collecting data about their catalogs, brands, products, and pricing as soon as they’re added.
Step 2. Monitor market activity
Open the Overview dashboard to review tracked sellers, active sellers, new brands, products added over the last 30 days, sourcing opportunities, competitor activity, the most active sellers, and trending brands.
This helps you identify market trends and prioritize opportunities before investigating individual competitors.
Step 3. Review your tracked competitors
Go to the Sellers dashboard to compare competitors by marketplace, seller type, catalog size, newly added products and brands, ratings, tracking history, notes, and last update.
Reviewing competitors side by side helps you identify the sellers with the most relevant sourcing strategies and recent catalog activity.
Step 4. Explore competitor insights
Open the Seller Details page by clicking a competitor’s name. Review the Insights, Brands, and Products tabs to analyze catalog overlap, recent activity, brand portfolios, product changes, and category distribution.
This gives you a complete picture of how each competitor builds and expands their catalog.
Step 5. Validate promising brands
When you discover an interesting brand, launch Brand Analyzer directly from Seller Spy.
This helps you evaluate demand, competition, Amazon’s presence, catalog depth, and resale potential before investing time in supplier outreach.
Step 6. Identify supply sources
Open AI Supplier Finder for brands you decide to pursue.
The tool helps you locate manufacturers, authorized distributors, and wholesalers connected to the brand, making it easier to move from research to supplier outreach.
Step 7. Evaluate product opportunities
Continue your research in Price List Analyzer to assess the products you’ve discovered.
Review profitability, ROI, competition, fees, restrictions, and other key metrics to determine which products meet your sourcing criteria.
Step 8. Build your sourcing pipeline
Use the insights gathered throughout the workflow to prioritize brands, contact suppliers, and source products with greater confidence.
By combining competitor intelligence with brand validation, supplier discovery, and product analysis, you can make sourcing decisions based on current marketplace data rather than guesswork.
FAQ
Can I track competitors in different Amazon marketplaces?
Yes. Seller Spy supports multiple Amazon marketplaces, allowing you to monitor competitors where you source and sell. Tracking sellers in different regions can also help you discover brands and products that haven’t yet gained traction in your primary marketplace.
What kind of competitors should I add to Seller Spy?
Focus on sellers whose business model matches yours, such as wholesale sellers, online arbitrage sellers, or dropshippers with similar catalogs. You can also track large marketplace sellers to identify emerging brands and sourcing trends, even if they operate at a different scale.
How do I know if a competitor is worth tracking?
Look for sellers that regularly introduce new brands, expand into different categories, or maintain large, active catalogs. Competitors with consistent catalog growth often provide more valuable sourcing insights than sellers whose inventory rarely changes.
Can Seller Spy help me find products before they become saturated?
It can help you identify products and brands shortly after competitors add them, giving you an opportunity to research them earlier. However, you should always validate demand, competition, profitability, and supplier availability before adding any product to your catalog.
Does Seller Spy replace product research tools?
No. Seller Spy helps you discover opportunities by monitoring competitor activity, but it doesn’t determine whether a product is profitable to sell. After identifying promising products or brands, you should use tools such as Brand Analyzer, AI Supplier Finder, and Price List Analyzer to complete your sourcing research before making purchasing decisions.
Final Thoughts
Finding profitable products is easier when you understand what successful competitors are doing. Seller Spy by Seller Assistant gives Amazon wholesale sellers, online arbitrage sellers, and dropshippers the visibility they need to monitor competitor activity, discover new brands and products, and identify sourcing opportunities before they become obvious to the broader market.
As part of Seller Assistant’s connected sourcing workflow, Seller Spy goes beyond competitor monitoring. You can validate promising brands with Brand Analyzer, find suppliers and distributors with AI Supplier Finder, and evaluate product profitability with Price List Analyzer – all within the same platform. By turning competitor insights into actionable sourcing decisions, Seller Spy helps you build a stronger catalog, source more efficiently, and stay competitive in the ever-changing Amazon marketplace.
Seller Assistant automates and connects every stage of your Amazon wholesale and arbitrage workflow. It brings together in one platform: workflow management tools – Purchase Orders Module, Suppliers Database, Product Database, Warehouses Database, FBA Shipments, bulk research & sourcing tools – Price List Analyzer, Bulk Restriction Checker, AI Supplier Finder, Brand Analyzer, Seller Spy, Chrome extensions – Seller Assistant Browser Extension, IP-Alert Extension, and built-in VPN by Seller Assistant, and integrations & team access features – seamless API connectivity, integrations with Zapier, Airtable, and Make, and Virtual Assistant Accounts.
