How we check discounts
By the Drop N Alert team · Updated
In short: we save every price we see for every product, and a discount counts as real only when we saw the product at its higher price first. This page explains each label you see on Drop N Alert.
What we record
We read prices from each brand's own online store. Products people watch are checked several times a day; the rest of the catalogue is checked at least once a day.
Every price we see is saved with the date, so each product builds up its own price history. We never set prices and we don't sell anything: you buy on the brand's site.
A real price drop
For every product we keep the highest price we have recorded since we started tracking it. When the current price is below that, the difference is a drop we saw ourselves, not the store's printed "before" price.
A discount is marked as verified when, at some point, we recorded the product at (or within 10% of) the store's "before" price. So the product really was sold at that price before the sale.
Always on sale
If a product has shown the same "sale" price for the whole time we've tracked it (at least 30 days) and we never saw it at the store's "before" price, we mark it as always on sale. The discount label is real on the page, but the price never actually came down.
We only give this label after 30 days of tracking, so new products are neither verified nor always on sale until we know more.
Lowest price in 90 days
A product is at its lowest price in 90 days when its current price is lower than anything we recorded in the previous 90 days, and our history for it goes back at least 30 days. The label shows for up to 30 days while that price holds.
Sale-event pages (White Friday, Blessed Friday, 11.11)
Products listed on a sale-event page must be at least 20% below the highest price we've recorded, must have dropped in the last 30 days, must not be always on sale, and must be within 15% of their lowest price in the last 90 days.
The last rule keeps out products whose price was raised shortly before a sale and then "cut" back. The 15% allowance keeps genuine sales from brands that ran a slightly deeper flash sale earlier, such as on 11.11.
Limits
We only see what a store shows publicly. Coupon codes, bank discounts and prices that change at checkout are not included.
Prices can change between our checks, and a new product has little or no history yet. Always confirm the price on the brand's site before you buy.
Our event reports count each product's most recent recorded drop, so they are produced shortly after the event.
See it in use: White Friday & Blessed Friday sale · Recent price drops · FAQ