Before you cut prices, see what it really costs
Why 10% off is bigger than it looks
A discount comes straight off your margin, not your price. If you keep 38% margin and give 10% off, you've given away more than a quarter of your profit per unit — so you need a lot more volume just to stand still.
Before running a promotion, check the break-even volume here. If it's more than the promotion can realistically drive, offer added value (a free add-on, faster delivery) instead — it protects margin and feels just as generous.