Resellers obsess over price and ignore the number that actually decides whether something is worth their time: how fast it sells. A £200 item that sells once a year is a worse buy than an £8 item that sells ten times a week. Price is half the picture. Velocity is the other half.
What sales velocity means
Sales velocity is simply how many units sell over a period of time. Ten sales in a week is fast. Ten sales in a year is dead stock with a nice price tag. You cannot see it on a live listing, but you can work it out from an item's sold history.
How to estimate it
Open the sold history for a listing (the sold history viewer is the quick way, and there is a full guide to finding it if you need it). Then count:
- How many sales in the last 7 days.
- How many in the last 30 days.
- Whether those sales are spread evenly or bunched up.
Multiply the recent rate out. Six sales in the last week is roughly 300 a year if it holds. One sale in the last month is roughly a dozen a year. That back-of-the-envelope figure is usually enough to make a sourcing decision.
Read the pattern, not just the count
The shape of the sales matters as much as the total:
- Steady. A sale every few days, month after month. This is the dream: predictable, easy to plan stock around.
- Spiky. Nothing for weeks, then five in two days. Often a trend, a restock, or a price drop. It can be lucrative, but it is harder to rely on.
- Front-loaded then quiet. Lots of early sales, then a trickle. The market may be drying up, or everyone who wanted one already has it.
Sell-through rate: the other half
Velocity tells you how often it sells. Sell-through tells you how often a listing succeeds. Roughly, it is the number of sold listings divided by the total listings (sold plus active) for that item. If twenty are listed and only two have sold, that is weak demand in a crowded market. If two are listed and both sold quickly, that is strong demand and thin supply, which is exactly what you want to be selling into.
You can gauge it fast: search the item, note how many active listings there are, then filter to sold and see how many went. A high sold count against few active listings is a green light.
Using it to source
This is where it pays off. Before you buy a pallet, a job lot, or even a single item to flip, ask the velocity question first:
- Do not buy fifty of something that sells once a month. You will be sitting on it for years.
- A smaller margin on a fast seller usually beats a fat margin on a slow one, because your money keeps moving.
- If velocity is high and sell-through is high, you can price competitively and still shift volume.
Price and velocity together
The two numbers only make sense side by side. Work out the realistic price first (I covered that in researching eBay prices), then weigh it against how fast the thing moves. The sweet spot is a healthy price on something that sells steadily. Chase price alone and you end up with valuable stock you cannot shift.
Next time you are about to buy stock, pull the sold history and count the sales before you commit. It is the cheapest research you will ever do, and it is the one that stops you buying dead stock. The sold history viewer will get you the numbers in a few seconds.