Candy sells more in October, sunscreen in June, calendars in January. A seasonal product bought at the right time is one of the best orders you can place; bought a month late, it sits through the slow months and pays storage while it waits.
Reading a season
Look at the same weeks of past years on the listing's chart: how much faster it sold (the sales rank box), and how the price moved, around the same dates. Trust a season only when at least two past years agree, so one lucky December is not a season. With one past year on record, treat the pattern as a hint and size the order as if it weren't there. A listing whose PO Assistant read notes "Only 2 months of history" can't show you a season at all.
Write the season down in one line before you size the order, such as "Sells about 40% more in Nov and Dec. On sale by Oct 16."
The PO Assistant's suggested quantity doesn't count a season. It sizes from your share of the listing's sales today, so going into a peak it's the floor of what you might buy, and coming out of one it can be too much.
Timing: when your stock is on sale
What matters is not today's date but the day your stock is on sale. The Arrives mark on the chart is today plus your supplier's lead time, or 14 days when you haven't set one. Add the days for prep and for Amazon's warehouse to check the stock in, often a week to 10 days.
- Stock on sale before the peak can be sized on the faster sales of the season.
- Stock on sale during the peak is sized only for the weeks of peak left, then the normal pace.
- Stock that would go on sale after the peak is sized on the slow weeks that follow, which often means one case or none.
Set each supplier's lead time so the timing is right. See Supplier minimums and lead times.
The cost of holding through Q4
Amazon charges about three times as much to store a unit from October to December. A seasonal order that lands early pays that rate for longer. Count the storage for the days the stock sits: a peak order bought too early can earn less than you expect. See Amazon fees, storage and your costs.
After the peak
The weeks after a season are the risk: sales drop and the sellers who bought too much cut the price to clear it. Buy a product whose season is ending only for what will sell before the drop. If the PO Assistant flags Sellers piling in or a Price war as the season ends, the clearing sale has started.
A worked example
A gift tin sells about 60 a month for you most of the year, 2 a day. In the past two years it sold about 40% more in November and December, both years: 2.8 a day. Today is September 20 and your supplier's lead time is 16 days, so the Arrives mark sits on October 6. Allow 10 days to reach Amazon and be checked in: on sale about October 16, two weeks before the peak.
Your order should last 45 days: the first 15 are late October at the normal pace, the other 30 are November. Sized for the season, that's 2 a day for 15 days and 2.8 a day for 30: 114 tins, 19 cases of 6. The PO Assistant, which sizes on today's pace, suggests 15 cases, 90 tins. The 4 extra cases are your call, and two past years that agree are what make them a fair bet.
Bought in late November instead, the same order would be on sale in mid December, sized for two weeks of peak and the slow January after it: closer to the 15 cases, or fewer.