The Buy Box intelligence platform built for Amazon sellers.
Know every move. Win more.
SentryKit monitors every signal across your catalog and alerts you with full context. Hijackers, price changes, suppressed listings, competitor moves — their price, fulfillment type, account age, and seller profile — before you decide anything. Not just what changed. Who changed it, why it matters, and what it means for your margin.
Lose the Buy Box and you've effectively lost the sale. Every hour you're not holding it, a competitor captures revenue that's yours — on your own listing.
20+
Alert types monitored per product
Buy Box, hijackers, listing health, product content, inventory, sales velocity, badges, and pricing — every signal that affects your sales, watched simultaneously.
30 days
Free trial
Full Buy Box intelligence from day one. Every alert lands with context: who moved, whether they're a real threat, and whether acting would breach your floor.
~90s
Before your competitors even notice
The moment something changes — a hijacker, a price drop, a suppression — you know. Not the next morning. Not after the damage compounds. In time to act.
Buy Box Intelligence · How It Works
Amazon sellers who win the Buy Box aren't faster. They're better informed.
The sellers who consistently win the Buy Box know something most don't: half the competitors who undercut you aren't worth matching. New accounts, FBM sellers, zero-feedback listings — SentryKit flags all of it in the same alert, so you hold your margin when everyone else is racing to the bottom.
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Buy Box & Pricing Alerts
The moment your Buy Box status changes — won, lost, suppressed — you know. With the exact price gap, competitor fulfillment type, and whether matching is above your floor. No guesswork, no lag.
New seller on your ASIN? SentryKit profiles them immediately — account age, feedback count, FBA or FBM, US-based or overseas. Know whether you're looking at a real hijacker or a 3-day-old account that'll be gone by the weekend.
Hijacker DetectedSeller ProfileThreat Assessment
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Listing Health & Content Changes
Title edited, main image swapped, category changed, search results suppressed — each one affects Buy Box eligibility directly. SentryKit catches every change before it costs you ranking or revenue.
Content ChangedBuy Box SuppressedOut of Stock
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Inventory & Sales Velocity
FBA stock tracked against your live sales velocity — including units in transit. Get alerted before stock depletion hits your Buy Box eligibility, not after. A quiet day in sales doesn't go unnoticed either.
Low StockSales Volume DropDaily Portfolio Digest
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Exact gap — not a ballpark
The precise dollar amount between your price and the Buy Box winner. Not an estimate — the exact number, so you know whether a $1.50 move wins it back or a $6 drop is needed.
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Price floor always visible
Set your minimum based on landed cost. Every single alert shows whether matching to win the Buy Box is above your floor or below it. Intelligence, not autopilot.
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Seller signals — not just their price
FBA or FBM, feedback score, fulfillment type — for every competing offer. A zero-feedback FBM seller undercutting by $11 is a completely different situation from an established FBA brand $1.50 below you.
Buy Box & Pricing Alerts
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PRICE LANDSCAPE · MANUAL FOOD CHOPPER 5 CUP
US MARKETPLACE · BRAND: SQUAD HERO · ASIN: B08SHCHOP3
BUY BOX + FLOOR PRICE ALERT
Buy Box Lost - matching would breach your floor
BB PRICE
$17.99
Competitor winning
YOUR PRICE
$24.99
Active listing
PRICE GAP
$19.50
vs BB winner
BREACH BY
-$1.51
Below your floor
Do not match $17.99 - you'd be $1.51 below your floor — 8% margin — selling at a loss Floor: $19.50
Your Options
A
Hold your price - do not match. Their pricing is below your calculated break-even. Matching would mean selling at a loss.
B
Review your COGS inputs - confirm your floor price reflects your current costs.
C
Monitor and document this Seller ID - below-cost pricing is often unsustainable.
Hijacker & Competitor Intelligence
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PRICE LANDSCAPE · VEGETABLE PEELER DUAL BLADE
🇺🇸 US MARKETPLACE · BRAND: SQUAD HERO · ASIN: B08SHPEEL2
COMPETITOR ALERT
Unknown seller on your ASIN
THEIR PRICE
$21.49
Below your price
YOUR PRICE
$24.99
Current listing
BUY BOX
Lost to them
They're winning
FULFILLMENT
FBM
Not FBA
MARKET LANDSCAPE (COMPETITORS)
FBM Sellers8
Price Range$18 - $26
ActivityModerate
SELLER SIGNAL
Seller IDA3XYZ8FAKE001
Positive Feedback74% (112 ratings)
FulfillmentFBM - not fulfilled by Amazon
Your Options
A
Check Seller Central - look up this Seller ID and determine whether they are authorised. FBM at 74% feedback is a risk signal.
B
If brand owner-initiate Brand Registry report. Context: 8 FBM sellers in this category is moderate activity.
C
Document and monitor - their ID is logged. Full category landscape available in your dashboard.
Listing Health & Content Changes
✂️
PRICE LANDSCAPE · KITCHEN SCISSORS HEAVY DUTY
US MARKETPLACE · BRAND: SQUAD HERO · ASIN: B08SHSCIS4
LISTING HEALTH
Your listing has been suppressed
STATUS
SUPPRESSED
Competitor winning
DETECTED
JUST NOW
3:42 PM UTC
REASON
MISSING ATTRIBUTE
Competitor winning
Note - this is suppression, not a Buy Box loss. A suppressed listing has no Buy Box at all. No competitor is winning it - the listing is invisible to buyers.
Your Options
A
Go to Seller Central now - check for a case ID, policy notice, or listing quality issue flagged by Amazon.
B
Check listing quality - missing images, incomplete attributes, and pricing violations are the most common suppression triggers.
C
No price action will resolve this - this is a listing health issue. Direct intervention in Seller Central is required.
Inventory & Sales Velocity
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PRICE LANDSCAPE · BAMBOO CUTTING BOARD
🇺🇸 US MARKETPLACE · BRAND: SQUAD HERO · ASIN: B082XJRTMG
SALES VOLUME SPIKE - ACT ON INVENTORY
Sales Up 71% ~5 Days Of Stock Cover
UNITS SOLD
24
this week / 14 avg baseline
CHANGE
+71%
vs 14-day rolling avg
STOCK COVER
5 Days
urgent · 18 units at 3.4/day
· spike threshold crossed: +71% actual. your limit: +50%
· buy box: owned — protect this position during the spike
· critical: ~5 days of cover at spike rate. fba lead time is typically 5-10 days - act today.
Your Options
A
Create a replenishment shipment now - at 5 days cover and 5-10 day FBA lead times, you risk going OOS before stock arrives.
B
Check for inbound shipments already in transit - confirm pending transshipment quantity before ordering.
C
Investigate the cause of the spike - is this a promotion, external feature, or seasonal demand?
Monitoring Coverage
20+ alert types. Every layer of your listing. Nothing missed. Nothing late.
Most tools alert you on one or two signals. SentryKit monitors everything that moves your Buy Box and your revenue — Buy Box status, competitor moves, listing health, product content, inventory, sales velocity, badges, and pricing — simultaneously, for every product in your portfolio.
Competitor Price ChangeExact delta vs. your price — flags whether the move threatens your Buy Box position
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Listing Health
Suspended Listings
Search Suppression
Add-to-Cart Button
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Product Content
Product Details Change
Main Image
Category Change
Parent Product Change
A+ Content
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Inventory
FBA Stock (Out of Stock)
FBA Stock (Low Stock)
FBM Stock
Sales Volume Drop / Spike
FBA Fee Change
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Badges & Visibility
Best Seller Badge
Prime Badge
Amazon's Choice
Subscribe & Save
From sellers who made the switch
Why sellers who want control choose SentryKit over automation.
,,
I manage 6 seller accounts. The portfolio-level view is the thing — I know every morning what needs attention across all my clients before any of them message me. Buy Box status, stock warnings, listing issues in one place.
DL
Daniel L.★★★★★
Amazon Agency · 6 Accounts
,,
Caught a hijacker on a Sunday night within minutes. My old tool flagged it Monday morning. The price floor feature is the thing I didn't know I needed — I can see whether matching actually makes sense before doing anything. I've stopped three unnecessary price wars since switching.
MR
Marcus R.★★★★★
FBA Private Label · 180 ASINs
,,
After my repricer made some unexpected moves overnight I needed something that showed me what was happening without automating anything else. SentryKit is exactly that — visibility without interference. I use both now.
SK
Sarah K.★★★★★
Wholesale FBA · UK + US
Real-time, not batch
Every critical event fires the moment it happens. By the time your morning coffee brews, you've already responded.
Floor visible on every alert
Every single alert — Buy Box Lost, Competitor Price Change, Price Floor Breach — shows your margin floor alongside the gap. Match or hold is your call, made with full context.
Seller profile in the alert
Account age, feedback count, FBA or FBM — every competing offer profiled. Know before you decide.
Built for every seller model
The Buy Box works differently for everyone. SentryKit knows.
How you compete for the Buy Box depends entirely on your model. Private label sellers face hijackers. Wholesale sellers fight a crowded offer landscape. OA sellers run thin margins at high velocity. Agencies manage all of it across multiple accounts.
Your biggest threats are hijackers, unauthorised resellers, and listing changes you didn't make. When a hijacker appears on your ASIN, you need their account age, feedback count, and fulfillment type in the same alert — not just that they're there.
Hijacker Detected with full seller profile
Content Changed — title, image, category
Buy Box Suppressed vs Lost — clearly separated
Out of Stock alert before eligibility drops
Multiple sellers, one listing. Every move is visible.
You're competing on someone else's ASIN with sellers who know the listing as well as you do. Knowing their FBA status, account standing, and how their price compares to your floor changes your entire pricing strategy for how to win the buy box.
Buy Box Lost with competitor fulfillment type
Competitor Price Change with floor check
Price Floor Breach alert before you go negative
Full offer landscape per ASIN
Fast catalog. Thin margins. Know before you move.
OA is high velocity with tight margins. Amazon inventory alerts that catch stock depletion early and sales velocity drops that signal a Buy Box problem before your payout report does — that's the difference between a profitable month and a write-off.
Low Stock alert against live sales velocity
Sales Volume Drop before it hits revenue
Buy Box Lost with exact gap to floor
Daily Portfolio Digest across your full catalog
All your clients. One view. No surprises.
Managing multiple seller accounts means Buy Box health across all of them — not 15 separate dashboards. Every issue flagged before a client notices a revenue dip. Separate enterprise pricing for agencies managing 5+ accounts.
Cross-account Buy Box dashboard
Margin Threshold alerts per account
Priority alerts across all ASINs
Agency pricing
Pricing
Straightforward pricing. Start free. Upgrade when it matters.
Every tier includes all 20+ alert types. The difference is speed, history depth, and intelligence level — with a 30-day free trial included
Starter
$19/mo
$15/mo
$19/mo billed monthly
↑ Up to 2,000 orders/mo
For growing sellers who need to act fast. Real-time alerts so you're never the last to know.
Competitor seller profiles on every Buy Box event — name, location, storefront size, feedback rating
US-based vs. overseas flag on every competing seller
Seller re-occurrence detection — know when the same competitor keeps showing up
Pricing & Margin Control
Margin Threshold alerts — notified when margin drops below your configured minimum
Full COGS — referral fees + FBA fees pulled automatically, not manual estimates
History & Support
Buy Box history
Priority support
Pro grows with you: +$8 per 1,000 orders beyond 10K orders
Coming Soon
Threat level scoring — High / Medium / Low based on fulfillment type, rating, and scale
Price Floor enforcement — auto-fetched Amazon fees via SP API, recalculates when your price changes
AI Mode — ask questions about your portfolio in plain English Soon
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No hard cutoffs — ever. If orders spike during Q4 or a flash sale and you exceed your monthly limit, alerts keep running. You'll see a clear dashboard notification. We're not in the business of going dark when you need us most.
Global Coverage
Every Amazon marketplace. One platform.
Wherever you sell on Amazon, SentryKit monitors your Buy Box. Connect multiple marketplaces to one account.
