How we score deals

Most deal sites rank deals by votes or by what their editors like. We use rules anyone can read, applied to prices we check ourselves. Here they are.

What counts as a deal

Before a deal is shown, we check the price at the store. If it changed, the deal changes or goes away.
It has to be at least 10% below the store's own regular price, or at least 10% below what we've seen it sell for over the last 30 days. We only use our own price history once we have at least 3 days of prices.
A store claiming more than 50% off only counts if our own price history agrees.
Knock-off parts and accessories ("battery for Dyson…") are never deals.

Every live, checked deal gets a score from four parts:

The saving (up to 60 points): 1.5 points for each percent off. A drop we measured against the usual price we've recorded counts in full. A markdown the store claims counts at 75%, because stores set their own "was" prices.
Confirmed by our history (5 points): at least 10% below the usual price we've recorded.
Lowest in 90 days (20 points): at or below the lowest price we've recorded in the last 90 days, once we have a few days of prices and it has been higher.
Freshness (up to 15 points): 15 if we checked the price at the store in the last 6 hours, 8 in the last day.

Great deal: 75 or more. Good deal: 55 to 74. Fair deal: 35 to 54. Below that it's a small saving.

Some stores show a high "was" price the item never really sold for. We flag it and give that markdown no points when:

we've watched the item for at least 7 days and never saw it anywhere near that "was" price, or
it sells for about its usual price right now, while the store claims 15% off or more.

Nobody can pay for a higher score or a better spot.
Store commissions: some store links earn us a small commission, but they never change which deals we show or how they score.