What the till has never known

Every shopkeeper knows their top sellers. The till prints them.

No till has ever printed what any of it cost you. That number is on a supplier invoice in a box behind the counter, and it changes every time a rep walks in.

Stock Radar reads those invoices from a photograph. Then it does the arithmetic nobody has time for: what each line actually earns, what is about to run out, what next month’s deliveries will cost, and which of your best sellers is not paying its way.

The proof

Two things found in one shop’s own paperwork

These are two findings from a single Montreal corner store, in Canadian dollars. They are not promises about your shop. They are examples of the kind of thing that is sitting in yours.

The same beer, four times the margin

This shop buys Michelob two ways: a 473 ml can sold singly, and a 355 ml can bought twelve to a box. Per millilitre of beer, it pays the same money either way.

Cost — the 473 ml, singly	0.541¢ / ml
Cost — the 355 ml, by the dozen	0.542¢ / ml
Sells at — singly	1.104¢ / ml
Sells at — by the dozen	0.679¢ / ml
Margin — singly	0.562¢ / ml
Margin — by the dozen	0.137¢ / ml

Same beer, same cost per millilitre: it earns four times as much margin on a single. And that appears on no report anywhere, because a till lists products by name and never by what they cost.

More than a thousand dollars in a month, recorded as nothing

The same shop’s lottery terminal earns commission on every ticket it sells. It arrives on a Loto-Québec statement rather than through the till, so nobody had ever added it up. In July 2026, on the invoices a person had checked line by line, that came to:

Lottery commission, July 2026	more than C$1,000
What the books said it was	C$0

Nothing was found that was not already earned. It was simply invisible.

One shop, not an average. The beer figures were re-checked against that shop’s invoices on 23 September 2026; the lottery figure counts only invoices a person has confirmed.

What it does with the paperwork

None of this needs a cash register, a stock count or a migration.

It tells you what to buy, and when

Not from a stock count nobody has time to do — from the rhythm of your own deliveries. If cartons arrive every six days and it has been eleven, that is a fact about running out, and it comes off paper you already have.

It tells you what next month costs

Your buying rhythm, run forward and grouped by week and by supplier. Money out, in advance, so the cash-flow surprise stops being a surprise.

It tells you which shelf is thin

Margin per product, from the real cost, including the ones you would never have suspected.

It tells you what your paperwork has not told you yet

Tax on purchases, lottery commission, card fees, spoilage and staff consumption — the four buckets that quietly leave a shop and appear on no report.

And it says when it does not know

Where an invoice has not been confirmed or a receipt has not been read, every figure says so, in words, on the screen. A number this software cannot stand behind is a number it will not print.

Some of what it does works from your first week — what to reorder, what things really cost, what is owed in tax. Other things need a year of your history before they mean anything, and those screens will tell you the date they will be able to answer rather than showing you a chart built on one month. That is deliberate: advice built on too little is worse than no advice, because you act on it.

Your best-selling line might be your worst-earning one.