Bought in past month tracker: a daily history of Amazon’s demand badge

Under the review stars on an Amazon listing there is often a line like “2K+ bought in past month”. It is the closest thing Amazon gives a shopper, or a competitor, to a unit count. It is also gone the moment the page reloads with a different number: Amazon shows today’s value and keeps no history of it anywhere. AMZ Selling Tools reads the listing once a day and writes the figure down, so the badge becomes a series instead of a glance. Our guide to what “bought in past month” means covers the badge itself — the rounding, the thresholds and the limits; this page is about keeping a record of it.

Why the badge is worth recording

Every other demand signal on a listing is relative. Rank compares a product with its category and review counts pile up over years, so neither says what this month looks like against last. The badge is the one figure scoped to a window, which is exactly what makes it perishable:

• There is no history on Amazon’s side. The page renders one number. Yesterday’s is not stored, not linked and not recoverable, which is why a record has to start the day you decide to keep one.
• It moves without warning. A step up or down is the sort of thing you notice weeks late, if you are watching by eye — and only on the listings you happen to open.
• It disappears silently. Amazon shows no “fewer than 50 bought” message; the line simply is not there. Without a record you cannot tell a listing that dropped below the threshold from one that never carried the badge at all.

What the tracker stores

One column, Bought (Month), sits in the Product Info group of the grid beside the title, brand and availability. On every check the tracker stores the number without the plus sign — “100+ bought in past month” is kept as 100, and “2K+ bought in past month” as 2K, in the shorthand the page itself used.

• It is text, not a number. Amazon writes the figure in two different registers on the same site — plain digits at the low end and K or M shorthand higher up — so the value is stored exactly as written rather than expanded into a count we would have to invent. That is deliberate, and it is why the field takes text conditions rather than numeric thresholds.
• An empty cell is a reading, not a gap. When the page carries no badge the cell is left empty rather than filled with a zero. A run of values followed by blanks is a listing that fell out of the badge, and that is visible in the history.
• It never travels alone. The figure lands in the same row as everything else read on that visit — price, deal and coupon, the Buy Box winner, stock wording, the delivery promise, both rank slots and the review count. Ninety-two columns, one timestamp.

The badge is one of the 80 fields compared from one check to the next, so a move appears in the change history for that cell and in Diff View, with the date of the check that recorded it.

Alerts on the badge

The field is a text column, so it takes the four text conditions: changed, becomes, contains and stops containing. In practice:

• “Bought (Month) changed” — any step, in either direction, on the listings you apply the rule to. This is the one most people want.
• “Bought (Month) becomes 1K” — a listing you are watching crosses into the shorthand tier.

Two honest limits, worth knowing before you build a rule around them. There are no numeric thresholds on this field — no “drops below 500” — because the stored value is text and “1K” and “900” cannot be compared as numbers. And a rule compares one value with the previous one, so a badge appearing for the very first time, or vanishing altogether, is written to the history rather than emailed. The disappearance is recorded; it just does not ring a bell.

Benchmarking competitors with it

A tracked row is one ASIN in one location, so a competitor’s listing costs exactly what one of your own does and is read in exactly the same way. Put ten rivals and your own product in the same view and the badge becomes a monthly demand column across the set — who is stepping up, who is sliding, and roughly when it started.

The figure is coarse by design: it is rounded down into wide steps, so a listing can sell substantially more without the number moving at all. Read it as a floor and a direction rather than a sales estimate, and read it next to the columns that move daily. A rival whose badge steps up in the week their Best Sellers Rank improves and their price drops is telling you a coherent story. Amazon has never published how the figure is calculated or what window “past month” covers, so treat it as a signal, not an audit.

Export: CSV, Google Sheets and the API

The column is included in every route out of the product, on every plan and with no add-on:

• CSV or TSV. Bought (Month) is one of the default export columns, and an export carries the full check-by-check history rather than only the latest row.
• Google Sheets. One copied Apps Script pulls the same columns into a tab in your own spreadsheet, which is the practical way to chart the badge over time — see Amazon data in Google Sheets.
• Read-only API. The field is bought_in_past_month in the product group, returned as a string such as "1K", or null when the badge was absent on that check.

Where it is tracked

Twelve Amazon marketplaces — the United States, United Kingdom, Germany, France, Italy, Spain, Poland, Sweden, the Netherlands, Belgium, Canada and Australia — from 22 shopper locations. The United States is checked from Brooklyn, Chicago, Dallas, Los Angeles, Denver and Miami Beach; Canada from Toronto, Ottawa, Montreal, Calgary, Edmonton and Vancouver; each of the other ten countries from one location in-country.

Whether the badge appears at all is Amazon’s decision, not ours. We have seen it in local wording on the US, UK, Canadian, Australian, German, French, Belgian, Italian, Spanish, Swedish and Dutch storefronts, and not once in our own captures of amazon.pl. The steps also differ between stores — the German pages we have seen write “7000+” where the US writes “7K+” — so the figure is best compared against the same listing’s own past rather than across borders. Whatever the page shows, the column stores it.

What it costs

A flat $0.10 per ASIN per month — 30 daily checks of all 92 columns, with alerts, CSV, Google Sheets and the API included. Fifty listings is $5.00 a month, whether they are yours or your competitors’. Every new account starts with a free 30-day trial of up to 10 products and 10 checks a day, with no card required — long enough to see the badge move on the listings you care about.

Read next

• What “X+ bought in past month” means — the badge itself: rounding, the steps we have observed, and what it cannot tell you.
• BSR tracker — the other demand signal, recorded on the same check, main and sub-category.
• Competitor tracker — the price, stock and Buy Box columns that explain a badge that moved.
• Listing monitoring — everything else on the page, compared check to check.