Most "70% off" labels are honest. Some are theater. A store picks a list price nobody pays, then "cuts" it forever. The number on the tag is real, the saving is not.
We run a deals site, so we read thousands of these labels a week. This is the checklist we use before an offer reaches our front page. It works for you too.
1. Ask what the price was last week
A real discount has a "before". If the product sold for $99 last week and still sells for $99 today with a red "50% off" sticker, the sticker is decoration.
Every discount on our site says what it is measured against: the store's own list price, or the deal site that reported it. When we cannot verify an offer, we say so in plain text. We would rather show a blank than a guess.
Free tools that do the same for Amazon: CamelCamelCamel and Keepa. Paste the product link, look at the chart. If the line has been flat for months, the "deal" is the regular price.
2. Distrust round percentages on unknown brands
"80% off" on a brand you have never heard of, sold only on one marketplace, with a $299 list price and a $59 sale price, is the classic pattern. The $299 was invented so the $59 looks small. Compare with a known brand in the same category: if the "discounted" price is still higher than a Sony or Anker at full price, the label is a trick.
3. Check the price at a second store
The same TV, laptop or vacuum usually sits at three or four retailers. If Best Buy, Walmart and Amazon all show $449, and one store shows "$449, was $699", the "was" is a fiction. We list the store on every offer for exactly this reason: open a second tab and look.
4. Read the fine print on refurbished and open-box
"$1,299 → $899" on a MacBook can be true and still not comparable, if the $899 is for a refurbished unit and the $1,299 is for a new one. Apple, Best Buy and eBay all label condition clearly. We put "Refurb" or "Open-box" in the title when the source tells us. If a listing hides the condition, treat it as used.
5. Watch for the "list price" that appears only on sale days
Some retailers raise the reference price the week before Prime Day or Black Friday, then "discount" back to the normal price. A price tracker catches this instantly: the "before" price only exists for seven days. Comparing the same model at a second store catches it too.
What we do about it
Every offer that reaches our showcase passes an automatic filter. It rejects generic "up to X% off" promotions with no product, requires a real discount from the source, and cuts refurbished Apple products below 20% off (Apple's refurb store runs between 15% and 25%, so under 20% is not a deal, it is Tuesday). When the source shows only a list price and a sale price, we display both and say which one the discount is measured against.
We are not perfect. If you find a fake discount on our site, email us (the address is on our privacy page). We remove it and, if the source repeats it, we drop the source.