Set the offer once. The box on your product page and the discount at checkout read the same offer, so the price a customer sees is the price they pay, down to the cent. Three kinds, each its own block: quantity tiers, a fixed bundle and a free gift. Each inherits your theme's colours, type and corners instead of bringing its own. The discount follows the quantity in the cart, not a click on the box. Type it by hand and the price is the same. One stylesheet, one small script, no tracking.

• Quantity tiers, fixed bundles and free gifts, each as its own theme block
• The box takes its colours, type and corners from your theme, not from us
• One offer, read by both the box and the checkout discount, so prices agree
• The discount follows the cart quantity, however the customer got there
• No tracking, no third-party requests, no web fonts, nothing left behind