In most cases, an invalid discount code means either that the action period has concluded or that a minimal order amount is required. You should see a notification when entering an invalid discount code.
"Can you give me another discount code?"
As much as we'd love to be infinitely generous, we sadly can't afford to hand out discount codes at random times, as our prices are already super competitive at all times. No worries though, with a bit of patience, you will get a new discount code. Just keep an eye for actions or promotions in our newsletter or on Facebook.