ReplenishRadar vs SoStocked: Amazon-Only vs Unified Shopify + Amazon Planning

If you are looking at a SoStocked alternative, the decision usually comes down to one question: is Amazon your only channel, or not?

SoStocked is a legitimate Amazon-first planning tool. It has been in market since 2019, was acquired by Carbon6, and is now part of SPS Commerce after the $210 million acquisition in January 2025. The forecasting is mature, it handles Amazon constraints well, and ProfitFlow gives Amazon sellers a decent profitability view for their FBA business.

But SoStocked is Amazon-only. Specifically, it is FBA-only for USA and EU. No Shopify integration. No FBM support (as of early 2026). If Amazon is your whole business, that is fine. If you sell anywhere else, you are looking at running SoStocked plus something else, which defeats the coordination story.

ReplenishRadar is built for sellers who run Shopify plus Amazon and want one coordinated plan across both channels.

Start a free 14-day trial and see your inventory health across channels in minutes. No implementation project. No sales call.

The real decision

Three questions in order.

1. Is Amazon your only channel? If yes and you have no plans to expand, SoStocked can fit. If no, or you sell on Shopify too, ReplenishRadar's multi-channel model is a better fit.

2. Do you use FBA exclusively? SoStocked only supports FBA sellers. If you use Fulfilled by Merchant or hybrid fulfillment, SoStocked does not cover that. I wrote about the FBA vs FBM planning differences if you are weighing your fulfillment split.

3. Do you want public pricing without a sales call? ReplenishRadar pricing is public ($99/$199/$499). SoStocked's inventory tier starts at $250/month, and onboarding typically involves a demo or sales conversation. Their $97/month ProfitFlow tier does not include inventory management.

What SoStocked actually does well

I am not going to talk down a tool that works for its audience. Here is where SoStocked is genuinely strong:

• Mature Amazon forecasting with seasonality, trend analysis, and promotion adjustments. SoStocked has been iterating on Amazon demand modeling since 2019, which gives it real depth for FBA-only sellers.
• 12-month demand horizon which is longer than most planning tools. If your buying cycle involves placing orders 6+ months ahead (common with ocean freight from Chinese suppliers), that horizon matters.
• FBA-specific workflows including restock suggestions, reorder alerts, and 60-day supply targeting. These are tuned for the Amazon restock cadence, not generic inventory workflows.
• ProfitFlow add-on for Amazon profitability visibility (SKU-level margin analysis). This is a genuine product for sellers who want to see margin per ASIN without building spreadsheets.
• Carbon6 / SPS Commerce suite if you are already using their other Amazon tools (PixelMe, D8aDriven, SellHound). The suite integration can reduce tool sprawl for Amazon-only sellers.

If you are a $2-20M Amazon-only seller running FBA in the US and EU, and you want an Amazon-first tool backed by a larger parent company, SoStocked is a real option.

Where SoStocked gets weaker

No Shopify integration. This is a structural limit, not a configuration gap. SoStocked does not connect to Shopify at all. If you have a Shopify store pulling from the same inventory pool as your Amazon FBA, SoStocked cannot see that demand, which means FBA restock timing will be off by however much Shopify is selling. For sellers doing 30-50% of revenue on Shopify (which is increasingly common), that blind spot is material.

No FBM support yet. SoStocked has publicly stated FBM forecasting is on the roadmap but not yet available. If you run any Merchant-Fulfilled SKUs, those are outside the tool. Given that Amazon's fulfillment fees have been climbing steadily (the 3.5% FBA surcharge arrived in April 2026), more sellers are moving to hybrid FBA/FBM models. A tool that cannot see FBM demand misses an expanding piece of the picture.

Amazon coverage is FBA USA and EU only. FBA in other geos and non-US marketplaces are not supported in the main forecasting workflow. Sellers expanding into Canada, Mexico, or Japan are on their own for those channels.

Acquisition stitching is visible. SoStocked sits inside SPS Commerce's broader B2B supply chain platform now. SPS Commerce is a $6+ billion market cap company focused on EDI trading networks and retail compliance, not direct-to-consumer e-commerce tooling. Product roadmap priority naturally shifts toward SPS's core customer base (enterprise retailers and suppliers), not mid-market Amazon sellers. Review-site feedback from 2025-2026 mentions UI inconsistency across the Carbon6 tool suite. Pricing across multiple Carbon6 products can require a spreadsheet to calculate your actual total cost.

Pricing jumped. SoStocked retired their order-volume tiers in early 2026. The cheapest plan with inventory features is now $250/month (ProfitFlow + Inventory). The $97/month ProfitFlow tier is profit dashboards only, not forecasting, no reorder alerts, no PO creation. That is a $150+/month gap over ReplenishRadar's $99 Standard plan, which includes forecasting, FBA workflows, and Shopify integration in one bundle.

What makes ReplenishRadar a better SoStocked alternative

The feature table below shows what is present. Here is why those gaps cost real money when you are running both Shopify and Amazon.

Your Shopify demand is invisible to SoStocked

This is the structural problem. SoStocked cannot connect to Shopify. If Shopify accounts for 30% of your unit sales and your FBA planning tool cannot see it, every reorder calculation is 30% wrong. Not approximately. Precisely.

I hear this story from sellers constantly. They run a Shopify promotion. Inventory drops at the 3PL. The FBA restock SoStocked recommended cannot ship because the units are gone. Amazon stocks out. Buy Box disappears. Rankings drop. The recovery takes weeks.

ReplenishRadar treats Shopify and Amazon as one planning problem. One forecast. One reorder recommendation. One view of how much to send to FBA given what Shopify is also selling. That coordination is not a nice-to-have when both channels pull from the same supply.

FBA is a planning workflow, not just restock alerts

SoStocked sends restock alerts. That is step one of a multi-step problem.

ReplenishRadar creates FBA inbound plans directly through Amazon's SP-API. No copy-paste into Seller Central. It suggests transfer quantities based on demand velocity, current FBA stock, and your inbound pipeline. And it tracks per-fulfillment-center receiving times so you know when one FC checks in shipments in 4 days while another takes 12.

That variance changes how much buffer you need and when to ship. Getting it wrong means either overshipping (storage fees, age-based surcharges) or undershipping (stockouts). Most sellers I talk to underestimate FBA receiving variance by 50% or more.

Supplier lead time drift gets caught

You enter a lead time into any inventory tool once. Then your supplier starts shipping in 28 days instead of 21. Your safety stock is wrong. Your reorder point is stale. You find out when the stockout hits.

ReplenishRadar's supplier scorecard tracks actual delivery performance against stated lead times from your PO history. When the numbers drift, your reorder points adjust. No spreadsheet to remember to update. No quarterly manual audit. Sellers I talk to lose $8,000-$15,000 per stockout event on a mid-volume SKU. Catching a 7-day lead time drift before it becomes a stockout pays for the tool several times over.

Constraint math is automatic

Here is a scenario every multi-channel seller hits: you need 847 units, but the supplier requires a minimum order of 500 with casepacks of 24 and you can only order in multiples of 6. What is the actual PO quantity?

ReplenishRadar resolves MOQ, casepack, and order multiple constraints simultaneously. Most tools handle MOQ alone. Manual rounding on the rest means ordering errors that either cost you overstock carrying costs or leave you short. On a $50 average cost item with a 200-unit rounding error, that is $10,000 in unnecessary inventory or a stockout worth more.

You know your cost before talking to anyone

ReplenishRadar publishes pricing on the website. $99/month for Standard (2,000 SKUs). $199/month for Growth (20,000 SKUs). $499/month for Scale (50,000 SKUs). Month-to-month. Cancel anytime. You can compare this page with our pricing page right now.

SoStocked's inventory tier starts at $250/month. That is the starting number. Final pricing depends on volume, and onboarding typically involves a sales conversation. We show both prices because you should be able to compare without a phone call.

Pricing side-by-side

	ReplenishRadar	SoStocked
Profit dashboards only	N/A (included in all tiers)	$97/mo (ProfitFlow)
Inventory + forecasting	$99/mo (Standard)	$250+/mo (ProfitFlow + Inventory)
Mid tier	$199/mo (Growth)	Not publicly listed
Top tier	$499/mo (Scale)	Not publicly listed
Profitability dashboard	Included in all tiers	Included in both tiers
Shopify integration	Included	Not available
Amazon FBA (USA)	Yes	Yes
Amazon FBA (EU)	Yes	Yes
Amazon FBM	Yes	Not currently supported
Free trial	14 days, self-serve	30 days, often demo-led
Setup path	Self-serve OAuth	Sales call / demo typically

SoStocked offers the longer trial (30 days vs 14). But the price gap is hard to ignore: $99/month for ReplenishRadar Standard versus $250+/month for SoStocked with inventory features. And ReplenishRadar's $99 tier already includes Shopify integration, something SoStocked does not offer at any price.

A Digital Commerce 360 analysis of the SPS Commerce acquisition noted the deal valued Carbon6 at roughly 4x revenue, suggesting a combined Carbon6 ARR around $50 million. That is meaningful revenue, but it also means product pricing needs to support enterprise-level parent company margins. Mid-market seller pricing tends to rise after acquisitions like this.

Feature matrix

Capability	ReplenishRadar	SoStocked
Amazon SP-API integration	Native, first-class	Native, first-class
Demand forecasting	Statistical model with accuracy scoring	Mature Amazon-only focus
Forecast accuracy validation	Yes, predictions vs actuals	Not a primary feature
FBA inbound plan creation through SP-API	Yes	Manual in Seller Central
FBA restock limit awareness	Yes	Yes
FBA per-FC receiving variance tracking	Yes	No
FBA transfer quantity suggestions	Yes, channel-aware	Amazon-focused
Manifest export	One-click, Amazon template format	Varies
FBM support	Yes	Not supported (on roadmap)
Amazon non-US/EU marketplaces	Supported via SP-API	USA and EU only
Shopify integration	Native OAuth	Not available
Multi-channel unified forecast	Yes	Amazon-only
Coordinated transfer planning	Yes, channel-aware	Amazon-focused
Safety stock with lead time variance	Automatic	Configurable
MOQ, casepack, order multiple enforcement	Automatic with constraint rounding	Varies
Supplier scorecard (stated vs actual lead time)	Yes	Supplier data, less scorecard depth
Ordering cadence per supplier	Yes	Not available
Profit Intelligence	Lost sales, overstock cost, cash flow across all channels	ProfitFlow, Amazon-only, separate add-on
AI agent integration (MCP)	MCP package for Claude, Cursor, custom agents	Not available
Pricing transparency	Public tiers, no sales call	Tiered, often demo-led

The multi-channel coordination problem

This is the single biggest reason sellers switch from an Amazon-only tool to ReplenishRadar. If you are drawing from a shared inventory pool (supplier warehouse or 3PL) that feeds both Shopify and Amazon FBA, your planning has to account for both channels. The multi-channel inventory challenges post goes deep on the math.

Here is the scenario I see constantly. A seller runs Shopify and Amazon. Their third-party warehouse sends inventory to Amazon FBA on demand. They use an Amazon-only planning tool for FBA restock. Shopify sits outside the planning tool.

Then Shopify runs a promotion. Sales spike on Shopify, inventory drops at the 3PL, and the 3PL can no longer ship the FBA restock the tool recommended. The seller stocks out on Amazon, which kills their Buy Box and rankings. The planning tool did not see the Shopify promotion coming because Shopify is not connected.

This is not a hypothetical. I hear it monthly. It is the structural gap in an Amazon-only planning tool when the seller is not actually Amazon-only.

According to Digital Commerce 360 research, over 60% of Amazon marketplace sellers also sell through at least one other channel. That means the majority of sellers who would consider SoStocked have demand that SoStocked cannot see.

What sellers say about SoStocked (public review patterns, 2024-2026)

SoStocked has limited presence on enterprise review platforms like G2 and Capterra (the product is not heavily listed on either). Most feedback comes from Amazon seller communities and affiliate review sites.

What people appreciate:

• The Amazon forecasting depth is real. Sellers with predictable FBA velocity praise the seasonality adjustments and restock suggestions.
• ProfitFlow's margin visibility per ASIN is useful for identifying which products are actually making money after all Amazon fees.
• The 30-day trial gives enough time to evaluate with real data. That is better than most competitors.

What keeps showing up as concerns:

• Post-acquisition pricing changes. Sellers who started on the old order-volume tiers report significantly higher renewal quotes after the Carbon6/SPS Commerce restructuring.
• UI inconsistency across Carbon6 tools. Navigation patterns and design language differ between SoStocked, ProfitFlow, and other suite products.
• No Shopify. This is the most commonly cited limitation by sellers who have grown beyond Amazon-only and need multi-channel visibility.
• FBM roadmap has been "coming soon" for over a year. Sellers who moved to hybrid fulfillment to manage costs are waiting.

The pattern is consistent: SoStocked gets praised for Amazon FBA forecasting depth but runs into limits when sellers need multi-channel coordination, FBM support, or predictable pricing.

What SoStocked does that ReplenishRadar does not

Being honest about tradeoffs:

• SoStocked's 12-month forecast horizon is longer than what ReplenishRadar surfaces by default. If long-horizon forecasting is critical to your buying cycle (common with ocean freight), that is a legitimate SoStocked strength.
• ProfitFlow's Amazon margin depth is mature given that SoStocked has been iterating on it for years as an Amazon-only tool. ReplenishRadar's Profit Intelligence is cross-channel but is younger.
• Deep Amazon marketing integration through the Carbon6 / SPS Commerce suite (PPC tools, keyword tools, etc.) is not something ReplenishRadar attempts to cover. If you want advertising and inventory planning in one vendor, the Carbon6 bundle offers that.

Switching from SoStocked to ReplenishRadar

What you keep:

• Amazon SP-API connection (re-auth takes under 5 minutes via ReplenishRadar)
• Historical Amazon sales data (re-syncs from SP-API)
• FBA forecasting and restock planning (comparable quality)

What you gain:

• Shopify integration with unified forecasting across channels
• FBM support if you need it
• FBA inbound plan creation directly through Amazon (no copy-paste to Seller Central)
• Supplier scorecard showing stated vs actual lead time performance
• Public pricing with no sales call required
• MCP package for AI agent integration (Claude, Cursor, custom agents)

What you give up:

• 12-month forecast horizon (ReplenishRadar surfaces shorter horizons by default)
• Deep integration with other Carbon6 / SPS Commerce tools if you use them
• ProfitFlow's Amazon-specific margin depth (ReplenishRadar's cross-channel view is broader but shallower per-channel)

Timeline:

Day	What happens
1	Connect Amazon via SP-API and Shopify via OAuth. Historical data syncs. About 10 minutes
2-7	ReplenishRadar populates forecasts. Compare against SoStocked's view
8-30	Run in parallel. Place a couple of FBA inbound plans through ReplenishRadar to validate the math
30+	Cancel SoStocked if the multi-channel story is working

Most sellers complete the evaluation in 2-3 weeks. The technical setup is minutes. The confidence-building parallel run is what takes the time.

Who should use each tool

SoStocked fits when:

• You are Amazon-only with no plans to expand
• You run FBA in USA or EU exclusively
• You want 12-month horizon forecasting
• You use other Carbon6 / SPS Commerce tools and want integration

ReplenishRadar fits when:

• You sell on Shopify and Amazon (or plan to)
• You use FBM or hybrid fulfillment
• You sell on Amazon marketplaces outside USA/EU
• You want public pricing and self-serve onboarding
• You want a unified multi-channel profit view, not Amazon-only
• You want AI agent access to your inventory data

Bottom line

If you are strictly Amazon-only, FBA-only, and in the USA or EU, SoStocked is a defensible choice. Verify current pricing with their team and confirm which features are bundled versus add-on, because the pricing structure has changed since the SPS Commerce acquisition.

If you sell anywhere else, if you use FBM, or if you want public pricing, ReplenishRadar is the better fit. The $150/month price difference at the entry tier ($99 vs $250) adds up to $1,800/year, and ReplenishRadar's $99 plan includes Shopify integration that SoStocked does not offer at any price.

Start a free 14-day trial - connect your stores, see your real stockout risk across channels.

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Related Reading:

• Amazon FBA Restock Strategies
• Multi-Channel Inventory Challenges
• FBA vs FBM Inventory Planning
• Connect an AI Agent to Your Amazon and Shopify Inventory
• Best Amazon FBA Inventory Tools
• Best Multi-Channel Inventory Software
• Lead Time Demand Formula for Reorder Points
• Inventory Forecasting 101

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Sources

Competitor information is based on publicly available data as of May 2026. Features and pricing may change.

• SoStocked pricing page
• SoStocked on SPS Commerce
• Carbon6 SoStocked overview
• SPS Commerce acquisition of Carbon6 (Jan 2025, GlobeNewsWire)
• SPS Commerce Carbon6 acquisition analysis (Digital Commerce 360)
• SPS Commerce investor relations announcement
• Amazon FBA fee schedule (Seller Central)
• ReplenishRadar pricing and features pages