Skip to content
Marginary
How it works The decision log Pricing Sign in Start free for 14 days Go to your dashboard

How it works

Four steps, and you can stop and come back.

Each step depends on the one before it, and Marginary knows which ones you've finished. Progress counts items that can really be priced, not steps you clicked through. An item with no cost and no floor is never priced, however far you get.

About 20 minutes with your costs to hand Emergency stop from the first hour
1

Connect Amazon

You grant permission to read your prices and, later, to change them. Marginary uses Amazon's Selling Partner API, so nothing depends on your password and you can revoke it from your Amazon account at any time.

Amazon US Amazon Canada Amazon UK Amazon Germany
2

Get your items

Pull your catalogue straight from Amazon, upload a CSV, or paste a block of spreadsheet cells in. The upload previews what it recognised, what it will create, and every bad row by row number — and writes nothing until you confirm. One unusable line does not fail the other forty-nine.

Imported items arrive paused. Run the pull twice and it updates rather than duplicating.

Import preview
Recognised and ready to create147
Already in your catalogue — will update32
Rows with a problem — listed by line number3
3

Tell us your costs

What you paid, shipping in, anything else. This is what makes the floor mean something. There's a spreadsheet-style grid for typing costs across hundreds of items — keyboard driven, and nothing saves until you save.

Your minimum can be a number, or a rule: keep at least 15% return on cost. Written as a rule, it stays correct when a fee changes instead of going stale.

Pick how to price

Start with Profit maximiser. It optimises inside your range, backs off when Amazon holds the Featured Offer, holds in a price war, and raises prices when you're running low on stock.

If you'd rather write rules, you can — a named, ordered list where the first match wins, with the plain-English description generated from the rule itself so it cannot drift from the behaviour. Or run rules first and hand anything they don't answer to the optimiser.

That is the last step. Pricing runs from then on, as often as you choose — every five minutes through to once a day — and only on the items you have finished. Setup tells you which those are, and why the rest are not.

147 items ready to price

32 are not: 29 have no cost, 3 have no minimum price. Those stay exactly where they are.

Price cut 09:42

Cut the price from $24.99 to $23.45 after the best rival offer undercut you to $23.40. Matching the lowest offer would have earned $0.62 less per day.

Safety

Two limits you can't turn off. Eight you set yourself.

All of them apply to everything — your own rules, our optimiser, and manual changes alike.

Cannot be switched off

Your price never leaves your range

Not by a rule, not by the optimiser, not by accident.

Cannot be switched off

An item with no cost basis is never priced

Checked before every single decision, not once at import.

Biggest jump in one change

As a percentage, a dollar amount, or both. The smaller one wins.

Changes per item per day

So your listing doesn't look unstable to buyers.

Changes across your whole shop per hour

One cap on everything, so nothing runs away.

Smallest change worth making

Pointless one-cent moves get skipped.

Price endings

Round to .99, .95 or .00. Always down, never up.

Price-war brake

When prices on a listing keep falling fast, Marginary stops following them down.

Wait while Amazon is selling

Amazon usually wins on price. Sitting still beats losing money.

Emergency stop

One button freezes every price where it is. Marginary keeps recording what it would have done, so you lose nothing by pressing it.

Straight answers

What it can't do, before you find out yourself.

Every repricer page promises the same six things. These are the edges of this one.

It is not real-time

The scheduler ticks every 30 seconds; the fastest cadence you can pick is five minutes. Rival movements are reported as minutes or hours ago, because that's the cadence.

Amazon only

US, Canada, UK and Germany. Walmart and eBay are not available.

Imports are capped

2,000 rows per CSV, and a catalogue pull stops at 500 items per run. Run it again for the rest.

It's statistics, not AI

A logistic model with calibration and a least-squares fit for demand. It's told you when it hasn't seen enough of a listing to be confident.

Replay has a limit

It can tell you what a strategy would have chosen in recorded conditions. It cannot tell you how your competitors would have reacted.

Some numbers are modelled

Profit per day mixes observed Amazon orders with modelled estimates, and says which is which. Featured Offer share is always measured.

Start at step one. Stop whenever you like.

Fourteen days free on Starter, and an emergency stop from the first hour.