Why "Free Shipping" on eBay Silently Cuts Your Margin

Listing an item on eBay at the same price you'd use on Poshmark or Mercari, with "free shipping" turned on, quietly costs you real money — because unlike Poshmark, eBay does not give you a free prepaid label. You're buying that label yourself either way, whether you charge for shipping separately or fold it into the price. If you fold it in without raising the price to cover it, you're just absorbing the cost silently, sale after sale.

How much does unadjusted eBay pricing actually cost you?

Here's the same $20 item, priced two different ways, both shipped via a 1 lb Pirate Ship label (~$7.25) with eBay's ~13.6% Final Value Fee plus a $0.40 per-order fee:

Approach	Listed price	You keep
Price copied straight from Poshmark/Mercari	$20.00	$9.63
Price adjusted to cover the shipping you're about to absorb	$27.25	$15.89

Same item, same buyer experience — "free shipping" either way — and a $6.26 difference in what actually lands in your pocket, just from whether the arithmetic happened before the listing went up.

What's the fix?

One step, every time you cross-list to eBay: take your Poshmark/Mercari price and add roughly what you'll actually pay for the label before you post it there. Don't copy the number over as-is. This is the single most common margin leak in cross-platform reselling — small on any one sale, real money over a full closet's worth of listings.