Most small eBay sellers manage stock the same way: look at the shelf, notice something's getting low, order more. That works fine until it doesn't. A product has a good week, you don't spot it, and by the time you've reordered it's been showing as out of stock for ten days.
Why running out hurts more on eBay
When a listing hits zero, one of two things happens. Either it ends, and you lose the sales history and watchers built up on it, or (if you use eBay's out of stock option) it stays live but disappears from search until you add stock.
Either way, you don't just lose the sales while it's out of stock. A listing that's been selling steadily tends to rank well, and a gap in sales can take a while to recover from once it's back. Buyers who couldn't find you will have bought from someone else, and some of them will keep buying from them.
So the cost of running out of a good seller is usually more than the sales you missed that week.
Work out how many days of stock you have
The most useful number isn't how many you have left. It's how many days that will last.
Take the number you sold over the last 30 days and divide by 30 to get your daily rate. Then divide what's left by that rate.
For example, you have 24 left and sold 60 in the last 30 days. That's 2 a day, so you have about 12 days of stock.
Twelve units of something that sells two a month is fine for half a year. Twelve units of something that sells two a day is nearly gone. Looking at days rather than units is what stops your best sellers sneaking up on you.
Know when to reorder
You want to reorder while you still have enough to cover the time it takes new stock to arrive, plus a bit extra in case sales pick up or the delivery is late.
Reorder when days of stock left is less than your supplier's lead time plus a safety margin.
If your supplier usually takes 7 days and you like a week of cushion, reorder anything with less than 14 days left. For stock coming from abroad, where lead times are long and unpredictable, you'll want a bigger margin.
Set a low stock number for each product based on this, rather than one number for everything. Three left might be plenty of warning for a slow item and far too little for a fast one.
Variations need watching separately
If you sell clothes, phone cases or anything else with sizes and colours, the listing total can look healthy while the size everyone wants has run out. Buyers who can't get their size usually don't buy a different one. Track the quantity on each variation, not just the listing.
A simple weekly routine
- Sort your products by days of stock left, lowest first.
- Reorder anything below your reorder point. Don't wait until next week to see if it picks up.
- Check what's selling faster than usual. A product that sold 10 last month and 25 this month needs a bigger order than last time.
- Look at what's not selling. Stock that hasn't moved in three months is tying up money you could spend on things that sell.
Fifteen minutes once a week is enough for most small sellers. The hard part is remembering to do it in a busy week, which is exactly when stock runs out.
Keep quantities accurate on eBay
All of this relies on the numbers on eBay matching what's on your shelf. If you also sell in a shop, on your own website or on another marketplace, the quantity on eBay can drift. Either update it whenever you count stock, or use software that keeps the quantities in step across your channels. Selling something you don't have is worse than running out, as it means a cancellation, and cancellations count against your seller performance.